diff --git a/src/core/SkXfermode.cpp b/src/core/SkXfermode.cpp
index aeed9cc..7a25c6e 100644
--- a/src/core/SkXfermode.cpp
+++ b/src/core/SkXfermode.cpp
@@ -450,22 +450,22 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 
-bool SkXfermode::asCoeff(Coeff* src, Coeff* dst) {
+bool SkXfermode::asCoeff(Coeff* src, Coeff* dst) const {
     return false;
 }
 
-bool SkXfermode::asMode(Mode* mode) {
+bool SkXfermode::asMode(Mode* mode) const {
     return false;
 }
 
-SkPMColor SkXfermode::xferColor(SkPMColor src, SkPMColor dst) {
+SkPMColor SkXfermode::xferColor(SkPMColor src, SkPMColor dst) const{
     // no-op. subclasses should override this
     return dst;
 }
 
 void SkXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                         const SkPMColor* SK_RESTRICT src, int count,
-                        const SkAlpha* SK_RESTRICT aa) {
+                        const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     if (NULL == aa) {
@@ -489,7 +489,7 @@
 
 void SkXfermode::xfer16(uint16_t* dst,
                         const SkPMColor* SK_RESTRICT src, int count,
-                        const SkAlpha* SK_RESTRICT aa) {
+                        const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     if (NULL == aa) {
@@ -514,8 +514,7 @@
 
 void SkXfermode::xfer4444(SkPMColor16* SK_RESTRICT dst,
                           const SkPMColor* SK_RESTRICT src, int count,
-                          const SkAlpha* SK_RESTRICT aa)
-{
+                          const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     if (NULL == aa) {
@@ -540,8 +539,7 @@
 
 void SkXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                         const SkPMColor src[], int count,
-                        const SkAlpha* SK_RESTRICT aa)
-{
+                        const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     if (NULL == aa) {
@@ -569,7 +567,7 @@
 
 void SkProcXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                             const SkPMColor* SK_RESTRICT src, int count,
-                            const SkAlpha* SK_RESTRICT aa) {
+                            const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     SkXfermodeProc proc = fProc;
@@ -597,7 +595,7 @@
 
 void SkProcXfermode::xfer16(uint16_t* SK_RESTRICT dst,
                             const SkPMColor* SK_RESTRICT src, int count,
-                            const SkAlpha* SK_RESTRICT aa) {
+                            const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     SkXfermodeProc proc = fProc;
@@ -626,7 +624,7 @@
 
 void SkProcXfermode::xfer4444(SkPMColor16* SK_RESTRICT dst,
                               const SkPMColor* SK_RESTRICT src, int count,
-                              const SkAlpha* SK_RESTRICT aa) {
+                              const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     SkXfermodeProc proc = fProc;
@@ -655,7 +653,7 @@
 
 void SkProcXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                             const SkPMColor* SK_RESTRICT src, int count,
-                            const SkAlpha* SK_RESTRICT aa) {
+                            const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     SkXfermodeProc proc = fProc;
@@ -711,14 +709,14 @@
         fDstCoeff = rec.fDC;
     }
 
-    virtual bool asMode(Mode* mode) {
+    virtual bool asMode(Mode* mode) const SK_OVERRIDE {
         if (mode) {
             *mode = fMode;
         }
         return true;
     }
 
-    virtual bool asCoeff(Coeff* sc, Coeff* dc) {
+    virtual bool asCoeff(Coeff* sc, Coeff* dc) const SK_OVERRIDE {
         if (CANNOT_USE_COEFF == fSrcCoeff) {
             return false;
         }
@@ -765,8 +763,8 @@
 public:
     SkClearXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kClear_Mode) {}
 
-    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) SK_OVERRIDE;
-    virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) SK_OVERRIDE;
+    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
+    virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkClearXfermode)
 
@@ -778,7 +776,7 @@
 
 void SkClearXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT, int count,
-                             const SkAlpha* SK_RESTRICT aa) {
+                             const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && count >= 0);
 
     if (NULL == aa) {
@@ -796,7 +794,7 @@
 }
 void SkClearXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT, int count,
-                             const SkAlpha* SK_RESTRICT aa) {
+                             const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && count >= 0);
 
     if (NULL == aa) {
@@ -819,8 +817,8 @@
 public:
     SkSrcXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kSrc_Mode) {}
 
-    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) SK_OVERRIDE;
-    virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) SK_OVERRIDE;
+    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
+    virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSrcXfermode)
 
@@ -832,7 +830,7 @@
 
 void SkSrcXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                            const SkPMColor* SK_RESTRICT src, int count,
-                           const SkAlpha* SK_RESTRICT aa) {
+                           const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     if (NULL == aa) {
@@ -851,7 +849,7 @@
 
 void SkSrcXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                            const SkPMColor* SK_RESTRICT src, int count,
-                           const SkAlpha* SK_RESTRICT aa) {
+                           const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     if (NULL == aa) {
@@ -873,13 +871,13 @@
     }
 }
 
-////////////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
 
 class SkDstInXfermode : public SkProcCoeffXfermode {
 public:
     SkDstInXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kDstIn_Mode) {}
 
-    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) SK_OVERRIDE;
+    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDstInXfermode)
 
@@ -891,7 +889,7 @@
 
 void SkDstInXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT src, int count,
-                             const SkAlpha* SK_RESTRICT aa) {
+                             const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src);
 
     if (count <= 0) {
@@ -909,13 +907,13 @@
     } while (--count != 0);
 }
 
-/////////////////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
 
 class SkDstOutXfermode : public SkProcCoeffXfermode {
 public:
     SkDstOutXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kDstOut_Mode) {}
 
-    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) SK_OVERRIDE;
+    virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDstOutXfermode)
 
@@ -928,7 +926,7 @@
 
 void SkDstOutXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                               const SkPMColor* SK_RESTRICT src, int count,
-                              const SkAlpha* SK_RESTRICT aa) {
+                              const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src);
 
     if (count <= 0) {
@@ -1002,7 +1000,7 @@
     return true;
 }
 
-bool SkXfermode::AsMode(SkXfermode* xfer, Mode* mode) {
+bool SkXfermode::AsMode(const SkXfermode* xfer, Mode* mode) {
     if (NULL == xfer) {
         if (mode) {
             *mode = kSrcOver_Mode;
@@ -1012,14 +1010,14 @@
     return xfer->asMode(mode);
 }
 
-bool SkXfermode::AsCoeff(SkXfermode* xfer, Coeff* src, Coeff* dst) {
+bool SkXfermode::AsCoeff(const SkXfermode* xfer, Coeff* src, Coeff* dst) {
     if (NULL == xfer) {
         return ModeAsCoeff(kSrcOver_Mode, src, dst);
     }
     return xfer->asCoeff(src, dst);
 }
 
-bool SkXfermode::IsMode(SkXfermode* xfer, Mode mode) {
+bool SkXfermode::IsMode(const SkXfermode* xfer, Mode mode) {
     // if xfer==null then the mode is srcover
     Mode m = kSrcOver_Mode;
     if (xfer && !xfer->asMode(&m)) {
diff --git a/src/effects/SkArithmeticMode.cpp b/src/effects/SkArithmeticMode.cpp
index c999ce0..54a28ce 100644
--- a/src/effects/SkArithmeticMode.cpp
+++ b/src/effects/SkArithmeticMode.cpp
@@ -12,7 +12,7 @@
     }
 
     virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
-                        const SkAlpha aa[]) SK_OVERRIDE;
+                        const SkAlpha aa[]) const SK_OVERRIDE;
 
     SK_DECLARE_UNFLATTENABLE_OBJECT()
 
@@ -48,7 +48,7 @@
 }
 
 void SkArithmeticMode_scalar::xfer32(SkPMColor dst[], const SkPMColor src[],
-                                     int count, const SkAlpha aaCoverage[]) {
+                                 int count, const SkAlpha aaCoverage[]) const {
     SkScalar k1 = fK[0] / 255;
     SkScalar k2 = fK[1];
     SkScalar k3 = fK[2];
diff --git a/src/effects/SkAvoidXfermode.cpp b/src/effects/SkAvoidXfermode.cpp
index 89ae1f9..f39ee74 100644
--- a/src/effects/SkAvoidXfermode.cpp
+++ b/src/effects/SkAvoidXfermode.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2006 The Android Open Source Project
  *
@@ -6,13 +5,11 @@
  * found in the LICENSE file.
  */
 
-
 #include "SkAvoidXfermode.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
 
-SkAvoidXfermode::SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode)
-{
+SkAvoidXfermode::SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode) {
     if (tolerance > 255) {
         tolerance = 255;
     }
@@ -23,15 +20,13 @@
 }
 
 SkAvoidXfermode::SkAvoidXfermode(SkFlattenableReadBuffer& buffer)
-    : INHERITED(buffer)
-{
+    : INHERITED(buffer) {
     fOpColor = buffer.readColor();
     fDistMul = buffer.readUInt();
     fMode = (Mode)buffer.readUInt();
 }
 
-void SkAvoidXfermode::flatten(SkFlattenableWriteBuffer& buffer) const
-{
+void SkAvoidXfermode::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeColor(fOpColor);
@@ -40,8 +35,7 @@
 }
 
 // returns 0..31
-static unsigned color_dist16(uint16_t c, unsigned r, unsigned g, unsigned b)
-{
+static unsigned color_dist16(uint16_t c, unsigned r, unsigned g, unsigned b) {
     SkASSERT(r <= SK_R16_MASK);
     SkASSERT(g <= SK_G16_MASK);
     SkASSERT(b <= SK_B16_MASK);
@@ -54,8 +48,7 @@
 }
 
 // returns 0..15
-static unsigned color_dist4444(uint16_t c, unsigned r, unsigned g, unsigned b)
-{
+static unsigned color_dist4444(uint16_t c, unsigned r, unsigned g, unsigned b) {
     SkASSERT(r <= 0xF);
     SkASSERT(g <= 0xF);
     SkASSERT(b <= 0xF);
@@ -68,8 +61,7 @@
 }
 
 // returns 0..255
-static unsigned color_dist32(SkPMColor c, U8CPU r, U8CPU g, U8CPU b)
-{
+static unsigned color_dist32(SkPMColor c, U8CPU r, U8CPU g, U8CPU b) {
     SkASSERT(r <= 0xFF);
     SkASSERT(g <= 0xFF);
     SkASSERT(b <= 0xFF);
@@ -81,8 +73,7 @@
     return SkMax32(dr, SkMax32(dg, db));
 }
 
-static int scale_dist_14(int dist, uint32_t mul, uint32_t sub)
-{
+static int scale_dist_14(int dist, uint32_t mul, uint32_t sub) {
     int tmp = dist * mul - sub;
     int result = (tmp + (1 << 13)) >> 14;
 
@@ -94,8 +85,7 @@
 }
 
 void SkAvoidXfermode::xfer32(SkPMColor dst[], const SkPMColor src[], int count,
-                             const SkAlpha aa[])
-{
+                             const SkAlpha aa[]) const {
     unsigned    opR = SkColorGetR(fOpColor);
     unsigned    opG = SkColorGetG(fOpColor);
     unsigned    opB = SkColorGetB(fOpColor);
@@ -134,8 +124,7 @@
     }
 }
 
-static inline U16CPU SkBlend3216(SkPMColor src, U16CPU dst, unsigned scale)
-{
+static inline U16CPU SkBlend3216(SkPMColor src, U16CPU dst, unsigned scale) {
     SkASSERT(scale <= 32);
     scale <<= 3;
 
@@ -145,8 +134,7 @@
 }
 
 void SkAvoidXfermode::xfer16(uint16_t dst[], const SkPMColor src[], int count,
-                             const SkAlpha aa[])
-{
+                             const SkAlpha aa[]) const {
     unsigned    opR = SkColorGetR(fOpColor) >> (8 - SK_R16_BITS);
     unsigned    opG = SkColorGetG(fOpColor) >> (8 - SK_G16_BITS);
     unsigned    opB = SkColorGetB(fOpColor) >> (8 - SK_R16_BITS);
@@ -186,8 +174,7 @@
 }
 
 void SkAvoidXfermode::xfer4444(uint16_t dst[], const SkPMColor src[], int count,
-                               const SkAlpha aa[])
-{
+                               const SkAlpha aa[]) const {
     unsigned    opR = SkColorGetR(fOpColor) >> 4;
     unsigned    opG = SkColorGetG(fOpColor) >> 4;
     unsigned    opB = SkColorGetB(fOpColor) >> 4;
@@ -226,7 +213,7 @@
     }
 }
 
-void SkAvoidXfermode::xferA8(SkAlpha dst[], const SkPMColor src[], int count, const SkAlpha aa[])
-{
+void SkAvoidXfermode::xferA8(SkAlpha dst[], const SkPMColor src[], int count,
+                             const SkAlpha aa[]) const {
     // override in subclass
 }