Remove SkCanvas matrix ops return value.

The internal SkMatrix ops can no longer fail -> we can remove the bool
return value.

R=bsalomon@google.com, reed@google.com, robertphillips@google.com, scroggo@google.com, fmalita@google.com

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/200223008

git-svn-id: http://skia.googlecode.com/svn/trunk@13849 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 8e5f3ac..fa433b3 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -470,35 +470,30 @@
     /** Preconcat the current matrix with the specified translation
         @param dx   The distance to translate in X
         @param dy   The distance to translate in Y
-        returns true if the operation succeeded (e.g. did not overflow)
     */
-    bool translate(SkScalar dx, SkScalar dy);
+    void translate(SkScalar dx, SkScalar dy);
 
     /** Preconcat the current matrix with the specified scale.
         @param sx   The amount to scale in X
         @param sy   The amount to scale in Y
-        returns true if the operation succeeded (e.g. did not overflow)
     */
-    bool scale(SkScalar sx, SkScalar sy);
+    void scale(SkScalar sx, SkScalar sy);
 
     /** Preconcat the current matrix with the specified rotation.
         @param degrees  The amount to rotate, in degrees
-        returns true if the operation succeeded (e.g. did not overflow)
     */
-    bool rotate(SkScalar degrees);
+    void rotate(SkScalar degrees);
 
     /** Preconcat the current matrix with the specified skew.
         @param sx   The amount to skew in X
         @param sy   The amount to skew in Y
-        returns true if the operation succeeded (e.g. did not overflow)
     */
-    bool skew(SkScalar sx, SkScalar sy);
+    void skew(SkScalar sx, SkScalar sy);
 
     /** Preconcat the current matrix with the specified matrix.
         @param matrix   The matrix to preconcatenate with the current matrix
-        @return true if the operation succeeded (e.g. did not overflow)
     */
-    bool concat(const SkMatrix& matrix);
+    void concat(const SkMatrix& matrix);
 
     /** Replace the current matrix with a copy of the specified matrix.
         @param matrix The matrix that will be copied into the current matrix.
diff --git a/include/core/SkMatrix.h b/include/core/SkMatrix.h
index d7c163d..8394c38 100644
--- a/include/core/SkMatrix.h
+++ b/include/core/SkMatrix.h
@@ -218,57 +218,57 @@
     /** Set the matrix to skew by sx and sy.
     */
     void setSkew(SkScalar kx, SkScalar ky);
-    /** Set the matrix to the concatenation of the two specified matrices,
-        returning true if the the result can be represented. Either of the
-        two matrices may also be the target matrix. *this = a * b;
+    /** Set the matrix to the concatenation of the two specified matrices.
+        Either of the two matrices may also be the target matrix.
+        *this = a * b;
     */
-    bool setConcat(const SkMatrix& a, const SkMatrix& b);
+    void setConcat(const SkMatrix& a, const SkMatrix& b);
 
     /** Preconcats the matrix with the specified translation.
         M' = M * T(dx, dy)
     */
-    bool preTranslate(SkScalar dx, SkScalar dy);
+    void preTranslate(SkScalar dx, SkScalar dy);
     /** Preconcats the matrix with the specified scale.
         M' = M * S(sx, sy, px, py)
     */
-    bool preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py);
+    void preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py);
     /** Preconcats the matrix with the specified scale.
         M' = M * S(sx, sy)
     */
-    bool preScale(SkScalar sx, SkScalar sy);
+    void preScale(SkScalar sx, SkScalar sy);
     /** Preconcats the matrix with the specified rotation.
         M' = M * R(degrees, px, py)
     */
-    bool preRotate(SkScalar degrees, SkScalar px, SkScalar py);
+    void preRotate(SkScalar degrees, SkScalar px, SkScalar py);
     /** Preconcats the matrix with the specified rotation.
         M' = M * R(degrees)
     */
-    bool preRotate(SkScalar degrees);
+    void preRotate(SkScalar degrees);
     /** Preconcats the matrix with the specified skew.
         M' = M * K(kx, ky, px, py)
     */
-    bool preSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py);
+    void preSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py);
     /** Preconcats the matrix with the specified skew.
         M' = M * K(kx, ky)
     */
-    bool preSkew(SkScalar kx, SkScalar ky);
+    void preSkew(SkScalar kx, SkScalar ky);
     /** Preconcats the matrix with the specified matrix.
         M' = M * other
     */
-    bool preConcat(const SkMatrix& other);
+    void preConcat(const SkMatrix& other);
 
     /** Postconcats the matrix with the specified translation.
         M' = T(dx, dy) * M
     */
-    bool postTranslate(SkScalar dx, SkScalar dy);
+    void postTranslate(SkScalar dx, SkScalar dy);
     /** Postconcats the matrix with the specified scale.
         M' = S(sx, sy, px, py) * M
     */
-    bool postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py);
+    void postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py);
     /** Postconcats the matrix with the specified scale.
         M' = S(sx, sy) * M
     */
-    bool postScale(SkScalar sx, SkScalar sy);
+    void postScale(SkScalar sx, SkScalar sy);
     /** Postconcats the matrix by dividing it by the specified integers.
         M' = S(1/divx, 1/divy, 0, 0) * M
     */
@@ -276,23 +276,23 @@
     /** Postconcats the matrix with the specified rotation.
         M' = R(degrees, px, py) * M
     */
-    bool postRotate(SkScalar degrees, SkScalar px, SkScalar py);
+    void postRotate(SkScalar degrees, SkScalar px, SkScalar py);
     /** Postconcats the matrix with the specified rotation.
         M' = R(degrees) * M
     */
-    bool postRotate(SkScalar degrees);
+    void postRotate(SkScalar degrees);
     /** Postconcats the matrix with the specified skew.
         M' = K(kx, ky, px, py) * M
     */
-    bool postSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py);
+    void postSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py);
     /** Postconcats the matrix with the specified skew.
         M' = K(kx, ky) * M
     */
-    bool postSkew(SkScalar kx, SkScalar ky);
+    void postSkew(SkScalar kx, SkScalar ky);
     /** Postconcats the matrix with the specified matrix.
         M' = other * M
     */
-    bool postConcat(const SkMatrix& other);
+    void postConcat(const SkMatrix& other);
 
     enum ScaleToFit {
         /**
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 10ca95c..cd2065b 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1275,65 +1275,60 @@
     // Do nothing. Subclasses may do something.
 }
 
-bool SkCanvas::translate(SkScalar dx, SkScalar dy) {
+void SkCanvas::translate(SkScalar dx, SkScalar dy) {
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
-    bool res = fMCRec->fMatrix->preTranslate(dx, dy);
+    fMCRec->fMatrix->preTranslate(dx, dy);
 
     this->didTranslate(dx, dy);
-    return res;
 }
 
 void SkCanvas::didScale(SkScalar, SkScalar) {
     // Do nothing. Subclasses may do something.
 }
 
-bool SkCanvas::scale(SkScalar sx, SkScalar sy) {
+void SkCanvas::scale(SkScalar sx, SkScalar sy) {
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
-    bool res = fMCRec->fMatrix->preScale(sx, sy);
+    fMCRec->fMatrix->preScale(sx, sy);
 
     this->didScale(sx, sy);
-    return res;
 }
 
 void SkCanvas::didRotate(SkScalar) {
     // Do nothing. Subclasses may do something.
 }
 
-bool SkCanvas::rotate(SkScalar degrees) {
+void SkCanvas::rotate(SkScalar degrees) {
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
-    bool res = fMCRec->fMatrix->preRotate(degrees);
+    fMCRec->fMatrix->preRotate(degrees);
 
     this->didRotate(degrees);
-    return res;
 }
 
 void SkCanvas::didSkew(SkScalar, SkScalar) {
     // Do nothing. Subclasses may do something.
 }
 
-bool SkCanvas::skew(SkScalar sx, SkScalar sy) {
+void SkCanvas::skew(SkScalar sx, SkScalar sy) {
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
-    bool res = fMCRec->fMatrix->preSkew(sx, sy);
+    fMCRec->fMatrix->preSkew(sx, sy);
 
     this->didSkew(sx, sy);
-    return res;
 }
 
 void SkCanvas::didConcat(const SkMatrix&) {
     // Do nothing. Subclasses may do something.
 }
 
-bool SkCanvas::concat(const SkMatrix& matrix) {
+void SkCanvas::concat(const SkMatrix& matrix) {
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
-    bool res = fMCRec->fMatrix->preConcat(matrix);
+    fMCRec->fMatrix->preConcat(matrix);
 
     this->didConcat(matrix);
-    return res;
 }
 
 void SkCanvas::didSetMatrix(const SkMatrix&) {
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index 024fa1b..946bf75 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1056,10 +1056,7 @@
             pathPtr->transform(*prePathMatrix, result);
             pathPtr = result;
         } else {
-            if (!tmpMatrix.setConcat(*matrix, *prePathMatrix)) {
-                // overflow
-                return;
-            }
+            tmpMatrix.setConcat(*matrix, *prePathMatrix);
             matrix = &tmpMatrix;
         }
     }
@@ -1279,9 +1276,7 @@
     paint.setStyle(SkPaint::kFill_Style);
 
     SkMatrix matrix;
-    if (!matrix.setConcat(*fMatrix, prematrix)) {
-        return;
-    }
+    matrix.setConcat(*fMatrix, prematrix);
 
     if (clipped_out(matrix, *fRC, bitmap.width(), bitmap.height())) {
         return;
@@ -2394,7 +2389,8 @@
     if (!m.invert(&im)) {
         return false;
     }
-    return fDstToUnit.setConcat(im, this->getTotalInverse());
+    fDstToUnit.setConcat(im, this->getTotalInverse());
+    return true;
 }
 
 #include "SkColorPriv.h"
diff --git a/src/core/SkMatrix.cpp b/src/core/SkMatrix.cpp
index a34866f..0929440 100644
--- a/src/core/SkMatrix.cpp
+++ b/src/core/SkMatrix.cpp
@@ -247,35 +247,36 @@
     }
 }
 
-bool SkMatrix::preTranslate(SkScalar dx, SkScalar dy) {
+void SkMatrix::preTranslate(SkScalar dx, SkScalar dy) {
+    if (!dx && !dy) {
+        return;
+    }
+
     if (this->hasPerspective()) {
         SkMatrix    m;
         m.setTranslate(dx, dy);
-        return this->preConcat(m);
-    }
-
-    if (dx || dy) {
+        this->preConcat(m);
+    } else {
         fMat[kMTransX] += sdot(fMat[kMScaleX], dx, fMat[kMSkewX], dy);
         fMat[kMTransY] += sdot(fMat[kMSkewY], dx, fMat[kMScaleY], dy);
-
         this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
     }
-    return true;
 }
 
-bool SkMatrix::postTranslate(SkScalar dx, SkScalar dy) {
+void SkMatrix::postTranslate(SkScalar dx, SkScalar dy) {
+    if (!dx && !dy) {
+        return;
+    }
+
     if (this->hasPerspective()) {
         SkMatrix    m;
         m.setTranslate(dx, dy);
-        return this->postConcat(m);
-    }
-
-    if (dx || dy) {
+        this->postConcat(m);
+    } else {
         fMat[kMTransX] += dx;
         fMat[kMTransY] += dy;
         this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
     }
-    return true;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -321,15 +322,19 @@
     return true;
 }
 
-bool SkMatrix::preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
+void SkMatrix::preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
+    if (1 == sx && 1 == sy) {
+        return;
+    }
+
     SkMatrix    m;
     m.setScale(sx, sy, px, py);
-    return this->preConcat(m);
+    this->preConcat(m);
 }
 
-bool SkMatrix::preScale(SkScalar sx, SkScalar sy) {
+void SkMatrix::preScale(SkScalar sx, SkScalar sy) {
     if (1 == sx && 1 == sy) {
-        return true;
+        return;
     }
 
     // the assumption is that these multiplies are very cheap, and that
@@ -346,25 +351,24 @@
     fMat[kMPersp1] *= sy;
 
     this->orTypeMask(kScale_Mask);
-    return true;
 }
 
-bool SkMatrix::postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
+void SkMatrix::postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
     if (1 == sx && 1 == sy) {
-        return true;
+        return;
     }
     SkMatrix    m;
     m.setScale(sx, sy, px, py);
-    return this->postConcat(m);
+    this->postConcat(m);
 }
 
-bool SkMatrix::postScale(SkScalar sx, SkScalar sy) {
+void SkMatrix::postScale(SkScalar sx, SkScalar sy) {
     if (1 == sx && 1 == sy) {
-        return true;
+        return;
     }
     SkMatrix    m;
     m.setScale(sx, sy);
-    return this->postConcat(m);
+    this->postConcat(m);
 }
 
 // this guy perhaps can go away, if we have a fract/high-precision way to
@@ -436,28 +440,28 @@
     this->setSinCos(sinV, cosV);
 }
 
-bool SkMatrix::preRotate(SkScalar degrees, SkScalar px, SkScalar py) {
+void SkMatrix::preRotate(SkScalar degrees, SkScalar px, SkScalar py) {
     SkMatrix    m;
     m.setRotate(degrees, px, py);
-    return this->preConcat(m);
+    this->preConcat(m);
 }
 
-bool SkMatrix::preRotate(SkScalar degrees) {
+void SkMatrix::preRotate(SkScalar degrees) {
     SkMatrix    m;
     m.setRotate(degrees);
-    return this->preConcat(m);
+    this->preConcat(m);
 }
 
-bool SkMatrix::postRotate(SkScalar degrees, SkScalar px, SkScalar py) {
+void SkMatrix::postRotate(SkScalar degrees, SkScalar px, SkScalar py) {
     SkMatrix    m;
     m.setRotate(degrees, px, py);
-    return this->postConcat(m);
+    this->postConcat(m);
 }
 
-bool SkMatrix::postRotate(SkScalar degrees) {
+void SkMatrix::postRotate(SkScalar degrees) {
     SkMatrix    m;
     m.setRotate(degrees);
-    return this->postConcat(m);
+    this->postConcat(m);
 }
 
 ////////////////////////////////////////////////////////////////////////////////////
@@ -492,28 +496,28 @@
     this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
 }
 
-bool SkMatrix::preSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
+void SkMatrix::preSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
     SkMatrix    m;
     m.setSkew(sx, sy, px, py);
-    return this->preConcat(m);
+    this->preConcat(m);
 }
 
-bool SkMatrix::preSkew(SkScalar sx, SkScalar sy) {
+void SkMatrix::preSkew(SkScalar sx, SkScalar sy) {
     SkMatrix    m;
     m.setSkew(sx, sy);
-    return this->preConcat(m);
+    this->preConcat(m);
 }
 
-bool SkMatrix::postSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
+void SkMatrix::postSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
     SkMatrix    m;
     m.setSkew(sx, sy, px, py);
-    return this->postConcat(m);
+    this->postConcat(m);
 }
 
-bool SkMatrix::postSkew(SkScalar sx, SkScalar sy) {
+void SkMatrix::postSkew(SkScalar sx, SkScalar sy) {
     SkMatrix    m;
     m.setSkew(sx, sy);
-    return this->postConcat(m);
+    this->postConcat(m);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -588,21 +592,12 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 
-static inline int fixmuladdmul(float a, float b, float c, float d,
-                               float* result) {
-    *result = SkDoubleToFloat((double)a * b + (double)c * d);
-    return true;
+static inline float muladdmul(float a, float b, float c, float d) {
+    return SkDoubleToFloat((double)a * b + (double)c * d);
 }
 
-static inline bool rowcol3(const float row[], const float col[],
-                           float* result) {
-    *result = row[0] * col[0] + row[1] * col[3] + row[2] * col[6];
-    return true;
-}
-
-static inline int negifaddoverflows(float& result, float a, float b) {
-    result = a + b;
-    return 0;
+static inline float rowcol3(const float row[], const float col[]) {
+    return row[0] * col[0] + row[1] * col[3] + row[2] * col[6];
 }
 
 static void normalize_perspective(SkScalar mat[9]) {
@@ -612,7 +607,7 @@
     }
 }
 
-bool SkMatrix::setConcat(const SkMatrix& a, const SkMatrix& b) {
+void SkMatrix::setConcat(const SkMatrix& a, const SkMatrix& b) {
     TypeMask aType = a.getPerspectiveTypeMaskOnly();
     TypeMask bType = b.getPerspectiveTypeMaskOnly();
 
@@ -624,73 +619,52 @@
         SkMatrix tmp;
 
         if ((aType | bType) & kPerspective_Mask) {
-            if (!rowcol3(&a.fMat[0], &b.fMat[0], &tmp.fMat[kMScaleX])) {
-                return false;
-            }
-            if (!rowcol3(&a.fMat[0], &b.fMat[1], &tmp.fMat[kMSkewX])) {
-                return false;
-            }
-            if (!rowcol3(&a.fMat[0], &b.fMat[2], &tmp.fMat[kMTransX])) {
-                return false;
-            }
-
-            if (!rowcol3(&a.fMat[3], &b.fMat[0], &tmp.fMat[kMSkewY])) {
-                return false;
-            }
-            if (!rowcol3(&a.fMat[3], &b.fMat[1], &tmp.fMat[kMScaleY])) {
-                return false;
-            }
-            if (!rowcol3(&a.fMat[3], &b.fMat[2], &tmp.fMat[kMTransY])) {
-                return false;
-            }
-
-            if (!rowcol3(&a.fMat[6], &b.fMat[0], &tmp.fMat[kMPersp0])) {
-                return false;
-            }
-            if (!rowcol3(&a.fMat[6], &b.fMat[1], &tmp.fMat[kMPersp1])) {
-                return false;
-            }
-            if (!rowcol3(&a.fMat[6], &b.fMat[2], &tmp.fMat[kMPersp2])) {
-                return false;
-            }
+            tmp.fMat[kMScaleX] = rowcol3(&a.fMat[0], &b.fMat[0]);
+            tmp.fMat[kMSkewX]  = rowcol3(&a.fMat[0], &b.fMat[1]);
+            tmp.fMat[kMTransX] = rowcol3(&a.fMat[0], &b.fMat[2]);
+            tmp.fMat[kMSkewY]  = rowcol3(&a.fMat[3], &b.fMat[0]);
+            tmp.fMat[kMScaleY] = rowcol3(&a.fMat[3], &b.fMat[1]);
+            tmp.fMat[kMTransY] = rowcol3(&a.fMat[3], &b.fMat[2]);
+            tmp.fMat[kMPersp0] = rowcol3(&a.fMat[6], &b.fMat[0]);
+            tmp.fMat[kMPersp1] = rowcol3(&a.fMat[6], &b.fMat[1]);
+            tmp.fMat[kMPersp2] = rowcol3(&a.fMat[6], &b.fMat[2]);
 
             normalize_perspective(tmp.fMat);
             tmp.setTypeMask(kUnknown_Mask);
         } else {    // not perspective
-            if (!fixmuladdmul(a.fMat[kMScaleX], b.fMat[kMScaleX],
-                    a.fMat[kMSkewX], b.fMat[kMSkewY], &tmp.fMat[kMScaleX])) {
-                return false;
-            }
-            if (!fixmuladdmul(a.fMat[kMScaleX], b.fMat[kMSkewX],
-                      a.fMat[kMSkewX], b.fMat[kMScaleY], &tmp.fMat[kMSkewX])) {
-                return false;
-            }
-            if (!fixmuladdmul(a.fMat[kMScaleX], b.fMat[kMTransX],
-                      a.fMat[kMSkewX], b.fMat[kMTransY], &tmp.fMat[kMTransX])) {
-                return false;
-            }
-            if (negifaddoverflows(tmp.fMat[kMTransX], tmp.fMat[kMTransX],
-                                  a.fMat[kMTransX]) < 0) {
-                return false;
-            }
+            tmp.fMat[kMScaleX] = muladdmul(a.fMat[kMScaleX],
+                                           b.fMat[kMScaleX],
+                                           a.fMat[kMSkewX],
+                                           b.fMat[kMSkewY]);
 
-            if (!fixmuladdmul(a.fMat[kMSkewY], b.fMat[kMScaleX],
-                      a.fMat[kMScaleY], b.fMat[kMSkewY], &tmp.fMat[kMSkewY])) {
-                return false;
-            }
-            if (!fixmuladdmul(a.fMat[kMSkewY], b.fMat[kMSkewX],
-                    a.fMat[kMScaleY], b.fMat[kMScaleY], &tmp.fMat[kMScaleY])) {
-                return false;
-            }
-            if (!fixmuladdmul(a.fMat[kMSkewY], b.fMat[kMTransX],
-                     a.fMat[kMScaleY], b.fMat[kMTransY], &tmp.fMat[kMTransY])) {
-                return false;
-            }
-            if (negifaddoverflows(tmp.fMat[kMTransY], tmp.fMat[kMTransY],
-                                  a.fMat[kMTransY]) < 0) {
-                return false;
-            }
+            tmp.fMat[kMSkewX]  = muladdmul(a.fMat[kMScaleX],
+                                           b.fMat[kMSkewX],
+                                           a.fMat[kMSkewX],
+                                           b.fMat[kMScaleY]);
 
+            tmp.fMat[kMTransX] = muladdmul(a.fMat[kMScaleX],
+                                           b.fMat[kMTransX],
+                                           a.fMat[kMSkewX],
+                                           b.fMat[kMTransY]);
+
+            tmp.fMat[kMTransX] += a.fMat[kMTransX];
+
+            tmp.fMat[kMSkewY]  = muladdmul(a.fMat[kMSkewY],
+                                           b.fMat[kMScaleX],
+                                           a.fMat[kMScaleY],
+                                           b.fMat[kMSkewY]);
+
+            tmp.fMat[kMScaleY] = muladdmul(a.fMat[kMSkewY],
+                                           b.fMat[kMSkewX],
+                                           a.fMat[kMScaleY],
+                                           b.fMat[kMScaleY]);
+
+            tmp.fMat[kMTransY] = muladdmul(a.fMat[kMSkewY],
+                                           b.fMat[kMTransX],
+                                           a.fMat[kMScaleY],
+                                           b.fMat[kMTransY]);
+
+            tmp.fMat[kMTransY] += a.fMat[kMTransY];
             tmp.fMat[kMPersp0] = tmp.fMat[kMPersp1] = 0;
             tmp.fMat[kMPersp2] = 1;
             //SkDebugf("Concat mat non-persp type: %d\n", tmp.getType());
@@ -699,19 +673,22 @@
         }
         *this = tmp;
     }
-    return true;
 }
 
-bool SkMatrix::preConcat(const SkMatrix& mat) {
+void SkMatrix::preConcat(const SkMatrix& mat) {
     // check for identity first, so we don't do a needless copy of ourselves
     // to ourselves inside setConcat()
-    return mat.isIdentity() || this->setConcat(*this, mat);
+    if(!mat.isIdentity()) {
+        this->setConcat(*this, mat);
+    }
 }
 
-bool SkMatrix::postConcat(const SkMatrix& mat) {
+void SkMatrix::postConcat(const SkMatrix& mat) {
     // check for identity first, so we don't do a needless copy of ourselves
     // to ourselves inside setConcat()
-    return mat.isIdentity() || this->setConcat(mat, *this);
+    if (!mat.isIdentity()) {
+        this->setConcat(mat, *this);
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -1468,10 +1445,7 @@
     if (!proc(dst, &tempMap, scale)) {
         return false;
     }
-    if (!result.setConcat(tempMap, result)) {
-        return false;
-    }
-    *this = result;
+    this->setConcat(tempMap, result);
     return true;
 }
 
diff --git a/src/core/SkMatrixClipStateMgr.h b/src/core/SkMatrixClipStateMgr.h
index c4201f8..b227583 100644
--- a/src/core/SkMatrixClipStateMgr.h
+++ b/src/core/SkMatrixClipStateMgr.h
@@ -62,29 +62,29 @@
                 fMatrix.reset();
             }
 
-            bool preTranslate(SkScalar dx, SkScalar dy) {
+            void preTranslate(SkScalar dx, SkScalar dy) {
                 fMatrixID = -1;
-                return fMatrix.preTranslate(dx, dy);
+                fMatrix.preTranslate(dx, dy);
             }
 
-            bool preScale(SkScalar sx, SkScalar sy) {
+            void preScale(SkScalar sx, SkScalar sy) {
                 fMatrixID = -1;
-                return fMatrix.preScale(sx, sy);
+                fMatrix.preScale(sx, sy);
             }
 
-            bool preRotate(SkScalar degrees) {
+            void preRotate(SkScalar degrees) {
                 fMatrixID = -1;
-                return fMatrix.preRotate(degrees);
+                fMatrix.preRotate(degrees);
             }
 
-            bool preSkew(SkScalar sx, SkScalar sy) {
+            void preSkew(SkScalar sx, SkScalar sy) {
                 fMatrixID = -1;
-                return fMatrix.preSkew(sx, sy);
+                fMatrix.preSkew(sx, sy);
             }
 
-            bool preConcat(const SkMatrix& matrix) {
+            void preConcat(const SkMatrix& matrix) {
                 fMatrixID = -1;
-                return fMatrix.preConcat(matrix);
+                fMatrix.preConcat(matrix);
             }
 
             void setMatrix(const SkMatrix& matrix) {
@@ -285,29 +285,29 @@
 
     void restore();
 
-    bool translate(SkScalar dx, SkScalar dy) {
+    void translate(SkScalar dx, SkScalar dy) {
         this->call(kMatrix_CallType);
-        return fCurMCState->fMatrixInfo->preTranslate(dx, dy);
+        fCurMCState->fMatrixInfo->preTranslate(dx, dy);
     }
 
-    bool scale(SkScalar sx, SkScalar sy) {
+    void scale(SkScalar sx, SkScalar sy) {
         this->call(kMatrix_CallType);
-        return fCurMCState->fMatrixInfo->preScale(sx, sy);
+        fCurMCState->fMatrixInfo->preScale(sx, sy);
     }
 
-    bool rotate(SkScalar degrees) {
+    void rotate(SkScalar degrees) {
         this->call(kMatrix_CallType);
-        return fCurMCState->fMatrixInfo->preRotate(degrees);
+        fCurMCState->fMatrixInfo->preRotate(degrees);
     }
 
-    bool skew(SkScalar sx, SkScalar sy) {
+    void skew(SkScalar sx, SkScalar sy) {
         this->call(kMatrix_CallType);
-        return fCurMCState->fMatrixInfo->preSkew(sx, sy);
+        fCurMCState->fMatrixInfo->preSkew(sx, sy);
     }
 
-    bool concat(const SkMatrix& matrix) {
+    void concat(const SkMatrix& matrix) {
         this->call(kMatrix_CallType);
-        return fCurMCState->fMatrixInfo->preConcat(matrix);
+        fCurMCState->fMatrixInfo->preConcat(matrix);
     }
 
     void setMatrix(const SkMatrix& matrix) {
diff --git a/src/device/xps/SkXPSDevice.cpp b/src/device/xps/SkXPSDevice.cpp
index 595694c..05ab13a 100644
--- a/src/device/xps/SkXPSDevice.cpp
+++ b/src/device/xps/SkXPSDevice.cpp
@@ -1696,9 +1696,7 @@
             }
             platonicPath.transform(*prePathMatrix, skeletalPath);
         } else {
-            if (!matrix.preConcat(*prePathMatrix)) {
-                return;
-            }
+            matrix.preConcat(*prePathMatrix);
         }
     }
 
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index cd448b9..b1fa560 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -233,12 +233,7 @@
 
     const SkMatrix& inverse = this->getTotalInverse();
 
-    if (!fDstToIndex.setConcat(fPtsToUnit, inverse)) {
-        // need to keep our set/end context calls balanced.
-        this->INHERITED::endContext();
-        return false;
-    }
-
+    fDstToIndex.setConcat(fPtsToUnit, inverse);
     fDstToIndexProc = fDstToIndex.getMapXYProc();
     fDstToIndexClass = (uint8_t)SkShader::ComputeMatrixClass(fDstToIndex);
 
diff --git a/src/pdf/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index 66ddccf..b8e6818 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -983,10 +983,7 @@
             }
             origPath.transform(*prePathMatrix, pathPtr);
         } else {
-            if (!matrix.preConcat(*prePathMatrix)) {
-                // TODO(edisonn): report somehow why we failed?
-                return;
-            }
+            matrix.preConcat(*prePathMatrix);
         }
     }
 
diff --git a/tests/CanvasTest.cpp b/tests/CanvasTest.cpp
index 4b6f0fa..50371d1 100644
--- a/tests/CanvasTest.cpp
+++ b/tests/CanvasTest.cpp
@@ -312,14 +312,11 @@
 // Basic test steps for most virtual methods in SkCanvas that draw or affect
 // the state of the canvas.
 
-SIMPLE_TEST_STEP_WITH_ASSERT(Translate,
-    translate(SkIntToScalar(1), SkIntToScalar(2)));
-SIMPLE_TEST_STEP_WITH_ASSERT(Scale,
-    scale(SkIntToScalar(1), SkIntToScalar(2)));
-SIMPLE_TEST_STEP_WITH_ASSERT(Rotate, rotate(SkIntToScalar(1)));
-SIMPLE_TEST_STEP_WITH_ASSERT(Skew,
-    skew(SkIntToScalar(1), SkIntToScalar(2)));
-SIMPLE_TEST_STEP_WITH_ASSERT(Concat, concat(kTestMatrix));
+SIMPLE_TEST_STEP(Translate, translate(SkIntToScalar(1), SkIntToScalar(2)));
+SIMPLE_TEST_STEP(Scale, scale(SkIntToScalar(1), SkIntToScalar(2)));
+SIMPLE_TEST_STEP(Rotate, rotate(SkIntToScalar(1)));
+SIMPLE_TEST_STEP(Skew, skew(SkIntToScalar(1), SkIntToScalar(2)));
+SIMPLE_TEST_STEP(Concat, concat(kTestMatrix));
 SIMPLE_TEST_STEP(SetMatrix, setMatrix(kTestMatrix));
 SIMPLE_TEST_STEP(ClipRect, clipRect(kTestRect));
 SIMPLE_TEST_STEP(ClipPath, clipPath(kTestPath));