[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 9dcbfdbc38891c65deb30feb8bf047dfc42022c4..dd3cdb17a41ce5880fa2feeb402e827a212e8238 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -355,7 +355,7 @@ public:
         }
 
         if (fLooper) {
-            fLooper->init(canvas);
+            fLooperContext = fLooper->init(canvas, &fLooperContextAllocator);
             fIsSimple = false;
         } else {
             // can we be marked as simple?
@@ -398,6 +398,8 @@ private:
     bool            fDoClearImageFilter;
     bool            fDone;
     bool            fIsSimple;
+    SkDrawLooper::Context* fLooperContext;
+    SkDrawLooper::ContextAllocator fLooperContextAllocator;
 
     bool doNext(SkDrawFilter::Type drawType);
 };
@@ -406,6 +408,7 @@ bool AutoDrawLooper::doNext(SkDrawFilter::Type drawType) {
     fPaint = NULL;
     SkASSERT(!fIsSimple);
     SkASSERT(fLooper || fFilter || fDoClearImageFilter);
+    SkASSERT(!fLooper || fLooperContext);
 
     SkPaint* paint = fLazyPaint.set(fOrigPaint);
 
@@ -413,7 +416,7 @@ 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;
     }