Revert of Extract most of the mutable state of SkShader into a separate Context object. (https://codereview.chromium.org/207683004/)

Reason for revert:
Causing memory leaks in Chromium.

Original issue's description:
> Extract most of the mutable state of SkShader into a separate Context object.
>
> SkShader currently stores some state during draw calls via setContext(...).
> Move that mutable state into a separate SkShader::Context class that is
> constructed on demand for the duration of the draw.
>
> Calls to setContext() are replaced with createContext() which returns a context
> corresponding to the shader object or NULL if the parameters to createContext
> are invalid.
>
> TEST=out/Debug/dm
> BUG=skia:1976
>
> Committed: http://code.google.com/p/skia/source/detail?r=14216

R=scroggo@google.com, skyostil@chromium.org, tomhudson@chromium.org, senorblanco@chromium.org, reed@google.com, dominikg@chromium.org
TBR=dominikg@chromium.org, reed@google.com, scroggo@google.com, senorblanco@chromium.org, skyostil@chromium.org, tomhudson@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:1976

Author: bungeman@google.com

Review URL: https://codereview.chromium.org/241283003

git-svn-id: http://skia.googlecode.com/svn/trunk@14247 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkRadialGradient.cpp b/src/effects/gradients/SkRadialGradient.cpp
index bc2ea3b..1b9e725 100644
--- a/src/effects/gradients/SkRadialGradient.cpp
+++ b/src/effects/gradients/SkRadialGradient.cpp
@@ -157,36 +157,16 @@
     rad_to_unit_matrix(center, radius, &fPtsToUnit);
 }
 
-size_t SkRadialGradient::contextSize() const {
-    return sizeof(RadialGradientContext);
-}
-
-SkShader::Context* SkRadialGradient::createContext(const SkBitmap& device, const SkPaint& paint,
-                                                   const SkMatrix& matrix, void* storage) const {
-    if (!this->validContext(device, paint, matrix)) {
-        return NULL;
-    }
-
-    return SkNEW_PLACEMENT_ARGS(storage, RadialGradientContext, (*this, device, paint, matrix));
-}
-
-SkRadialGradient::RadialGradientContext::RadialGradientContext(
-        const SkRadialGradient& shader, const SkBitmap& device,
-        const SkPaint& paint, const SkMatrix& matrix)
-    : INHERITED(shader, device, paint, matrix) {}
-
-void SkRadialGradient::RadialGradientContext::shadeSpan16(int x, int y, uint16_t* dstCParam,
-                                                          int count) {
+void SkRadialGradient::shadeSpan16(int x, int y, uint16_t* dstCParam,
+                         int count) {
     SkASSERT(count > 0);
 
-    const SkRadialGradient& radialGradient = static_cast<const SkRadialGradient&>(fShader);
-
     uint16_t* SK_RESTRICT dstC = dstCParam;
 
     SkPoint             srcPt;
     SkMatrix::MapXYProc dstProc = fDstToIndexProc;
-    TileProc            proc = radialGradient.fTileProc;
-    const uint16_t* SK_RESTRICT cache = fCache->getCache16();
+    TileProc            proc = fTileProc;
+    const uint16_t* SK_RESTRICT cache = this->getCache16();
     int                 toggle = init_dither_toggle16(x, y);
 
     if (fDstToIndexClass != kPerspective_MatrixClass) {
@@ -207,12 +187,12 @@
         }
 
         RadialShade16Proc shadeProc = shadeSpan16_radial_repeat;
-        if (SkShader::kClamp_TileMode == radialGradient.fTileMode) {
+        if (SkShader::kClamp_TileMode == fTileMode) {
             shadeProc = shadeSpan16_radial_clamp;
-        } else if (SkShader::kMirror_TileMode == radialGradient.fTileMode) {
+        } else if (SkShader::kMirror_TileMode == fTileMode) {
             shadeProc = shadeSpan16_radial_mirror;
         } else {
-            SkASSERT(SkShader::kRepeat_TileMode == radialGradient.fTileMode);
+            SkASSERT(SkShader::kRepeat_TileMode == fTileMode);
         }
         (*shadeProc)(srcPt.fX, sdx, srcPt.fY, sdy, dstC,
                      cache, toggle, count);
@@ -409,16 +389,14 @@
 
 }  // namespace
 
-void SkRadialGradient::RadialGradientContext::shadeSpan(int x, int y,
-                                                        SkPMColor* SK_RESTRICT dstC, int count) {
+void SkRadialGradient::shadeSpan(int x, int y,
+                                SkPMColor* SK_RESTRICT dstC, int count) {
     SkASSERT(count > 0);
 
-    const SkRadialGradient& radialGradient = static_cast<const SkRadialGradient&>(fShader);
-
     SkPoint             srcPt;
     SkMatrix::MapXYProc dstProc = fDstToIndexProc;
-    TileProc            proc = radialGradient.fTileProc;
-    const SkPMColor* SK_RESTRICT cache = fCache->getCache32();
+    TileProc            proc = fTileProc;
+    const SkPMColor* SK_RESTRICT cache = this->getCache32();
     int toggle = init_dither_toggle(x, y);
 
     if (fDstToIndexClass != kPerspective_MatrixClass) {
@@ -438,12 +416,12 @@
         }
 
         RadialShadeProc shadeProc = shadeSpan_radial_repeat;
-        if (SkShader::kClamp_TileMode == radialGradient.fTileMode) {
+        if (SkShader::kClamp_TileMode == fTileMode) {
             shadeProc = shadeSpan_radial_clamp;
-        } else if (SkShader::kMirror_TileMode == radialGradient.fTileMode) {
+        } else if (SkShader::kMirror_TileMode == fTileMode) {
             shadeProc = shadeSpan_radial_mirror;
         } else {
-            SkASSERT(SkShader::kRepeat_TileMode == radialGradient.fTileMode);
+            SkASSERT(SkShader::kRepeat_TileMode == fTileMode);
         }
         (*shadeProc)(srcPt.fX, sdx, srcPt.fY, sdy, dstC, cache, count, toggle);
     } else {    // perspective case