Revert of 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 c1d2726d8c3a9b5ffc853a3adfc27a924758422d..569e9e59baca8bf97886536b51cf5f3d0f93bd2a 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -91,10 +91,32 @@
 };
 #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;
@@ -1913,6 +1935,8 @@
 }
 
 void SkCanvas::internalDrawPaint(const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kPaint_Type, NULL)
 
     while (iter.next()) {
@@ -1927,6 +1951,8 @@
     if ((long)count <= 0) {
         return;
     }
+
+    CHECK_SHADER_NOSETCONTEXT(paint);
 
     SkRect r, storage;
     const SkRect* bounds = NULL;
@@ -1955,6 +1981,8 @@
 }
 
 void SkCanvas::drawRect(const SkRect& r, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     SkRect storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -1974,6 +2002,8 @@
 }
 
 void SkCanvas::drawOval(const SkRect& oval, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     SkRect storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -1993,6 +2023,8 @@
 }
 
 void SkCanvas::drawRRect(const SkRRect& rrect, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     SkRect storage;
     const SkRect* bounds = NULL;
     if (paint.canComputeFastBounds()) {
@@ -2023,6 +2055,8 @@
 
 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()) {
@@ -2042,6 +2076,8 @@
 }
 
 void SkCanvas::drawPath(const SkPath& path, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     if (!path.isFinite()) {
         return;
     }
@@ -2317,6 +2353,8 @@
 
 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()) {
@@ -2331,6 +2369,8 @@
 
 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()) {
@@ -2345,6 +2385,8 @@
 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()) {
@@ -2359,6 +2401,8 @@
 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()) {
@@ -2374,6 +2418,8 @@
                             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()) {