Extract most of the mutable state of SkShader into a separate Context object.

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index c16ac9a09f0f9437841aadf95652074b93fa709f..307af20d6847bdeb58c06b9ddfb487a5a9709998 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -91,32 +91,10 @@ private:
 };
 #endif
 
-class AutoCheckNoSetContext {
-public:
-    AutoCheckNoSetContext(const SkPaint& paint) : fPaint(paint) {
-        this->assertNoSetContext(fPaint);
-    }
-    ~AutoCheckNoSetContext() {
-        this->assertNoSetContext(fPaint);
-    }
-
-private:
-    const SkPaint& fPaint;
-
-    void assertNoSetContext(const SkPaint& paint) {
-        SkShader* s = paint.getShader();
-        if (s) {
-            SkASSERT(!s->setContextHasBeenCalled());
-        }
-    }
-};
-
 #define CHECK_LOCKCOUNT_BALANCE(bitmap)  AutoCheckLockCountBalance clcb(bitmap)
-#define CHECK_SHADER_NOSETCONTEXT(paint) AutoCheckNoSetContext     cshsc(paint)
 
 #else
     #define CHECK_LOCKCOUNT_BALANCE(bitmap)
-    #define CHECK_SHADER_NOSETCONTEXT(paint)
 #endif
 
 typedef SkTLazy<SkPaint> SkLazyPaint;
@@ -1923,8 +1901,6 @@ void SkCanvas::drawPaint(const SkPaint& paint) {
 }
 
 void SkCanvas::internalDrawPaint(const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     LOOPER_BEGIN(paint, SkDrawFilter::kPaint_Type, NULL)
 
     while (iter.next()) {
@@ -1940,8 +1916,6 @@ void SkCanvas::drawPoints(PointMode mode, size_t count, const SkPoint pts[],
         return;
     }
 
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     SkRect r, storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -1969,8 +1943,6 @@ void SkCanvas::drawPoints(PointMode mode, size_t count, const SkPoint pts[],
 }
 
 void SkCanvas::drawRect(const SkRect& r, const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     SkRect storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -1990,8 +1962,6 @@ void SkCanvas::drawRect(const SkRect& r, const SkPaint& paint) {
 }
 
 void SkCanvas::drawOval(const SkRect& oval, const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     SkRect storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -2011,8 +1981,6 @@ void SkCanvas::drawOval(const SkRect& oval, const SkPaint& paint) {
 }
 
 void SkCanvas::drawRRect(const SkRRect& rrect, const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     SkRect storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -2043,8 +2011,6 @@ void SkCanvas::drawRRect(const SkRRect& rrect, const SkPaint& paint) {
 
 void SkCanvas::onDrawDRRect(const SkRRect& outer, const SkRRect& inner,
                             const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     SkRect storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -2064,8 +2030,6 @@ void SkCanvas::onDrawDRRect(const SkRRect& outer, const SkRRect& inner,
 }
 
 void SkCanvas::drawPath(const SkPath& path, const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     if (!path.isFinite()) {
         return;
     }
@@ -2341,8 +2305,6 @@ void SkCanvas::DrawTextDecorations(const SkDraw& draw, const SkPaint& paint,
 
 void SkCanvas::drawText(const void* text, size_t byteLength,
                         SkScalar x, SkScalar y, const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type, NULL)
 
     while (iter.next()) {
@@ -2357,8 +2319,6 @@ void SkCanvas::drawText(const void* text, size_t byteLength,
 
 void SkCanvas::drawPosText(const void* text, size_t byteLength,
                            const SkPoint pos[], const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type, NULL)
 
     while (iter.next()) {
@@ -2373,8 +2333,6 @@ void SkCanvas::drawPosText(const void* text, size_t byteLength,
 void SkCanvas::drawPosTextH(const void* text, size_t byteLength,
                             const SkScalar xpos[], SkScalar constY,
                             const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type, NULL)
 
     while (iter.next()) {
@@ -2389,8 +2347,6 @@ void SkCanvas::drawPosTextH(const void* text, size_t byteLength,
 void SkCanvas::drawTextOnPath(const void* text, size_t byteLength,
                               const SkPath& path, const SkMatrix* matrix,
                               const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type, NULL)
 
     while (iter.next()) {
@@ -2406,8 +2362,6 @@ void SkCanvas::drawVertices(VertexMode vmode, int vertexCount,
                             const SkColor colors[], SkXfermode* xmode,
                             const uint16_t indices[], int indexCount,
                             const SkPaint& paint) {
-    CHECK_SHADER_NOSETCONTEXT(paint);
-
     LOOPER_BEGIN(paint, SkDrawFilter::kPath_Type, NULL)
 
     while (iter.next()) {