[WIP] Add Context to SkDrawLooper.

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 08b09e8e2b6e970b06d93c0449b9af8859573173..a6a4bd5ac494fa60fd2d9c4ecbc0478ad68bbed7 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -29,6 +29,8 @@
 #include "GrRenderTarget.h"
 #endif
 
+#define kDrawLooperContextStorageLongCount    (sizeof(void*) + sizeof(int))
+
 // experimental for faster tiled drawing...
 //#define SK_ENABLE_CLIP_QUICKREJECT
 
@@ -356,7 +358,8 @@ public:
         }
 
         if (fLooper) {
-            fLooper->init(canvas);
+            fLooperContext = fLooper->init(canvas, fLooperContextStorage,
+                                           sizeof(fLooperContextStorage));
             fIsSimple = false;
         } else {
             // can we be marked as simple?
@@ -369,6 +372,10 @@ public:
             fCanvas->internalRestore();
         }
         SkASSERT(fCanvas->getSaveCount() == fSaveCount);
+        if (fLooper) {
+            SkASSERT(fLooperContext);
+            fLooperContext->cleanup(fLooperContextStorage);
+        }
     }
 
     const SkPaint& paint() const {
@@ -399,6 +406,8 @@ private:
     bool            fDoClearImageFilter;
     bool            fDone;
     bool            fIsSimple;
+    SkDrawLooper::DrawContext* fLooperContext;
+    uint32_t fLooperContextStorage[kDrawLooperContextStorageLongCount];
 
     bool doNext(SkDrawFilter::Type drawType);
 };
@@ -407,6 +416,7 @@ bool AutoDrawLooper::doNext(SkDrawFilter::Type drawType) {
     fPaint = NULL;
     SkASSERT(!fIsSimple);
     SkASSERT(fLooper || fFilter || fDoClearImageFilter);
+    SkASSERT(!fLooper || fLooperContext);
 
     SkPaint* paint = fLazyPaint.set(fOrigPaint);
 
@@ -414,7 +424,7 @@ bool AutoDrawLooper::doNext(SkDrawFilter::Type drawType) {
         paint->setImageFilter(NULL);
     }
 
-    if (fLooper && !fLooper->next(fCanvas, paint)) {
+    if (fLooper && !fLooperContext->next(fCanvas, paint)) {
         fDone = true;
         return false;
     }