[WIP] Add Context to SkDrawLooper.

src/core/SkDrawLooper.cpp

Index: src/core/SkDrawLooper.cpp
diff --git a/src/core/SkDrawLooper.cpp b/src/core/SkDrawLooper.cpp
index bac2d969c0505d318fe7881c638c1a4750544fd3..56d76fffc141ac124f4b8bdce1b6a58df7182da5 100644
--- a/src/core/SkDrawLooper.cpp
+++ b/src/core/SkDrawLooper.cpp
@@ -13,31 +13,37 @@
 
 bool SkDrawLooper::canComputeFastBounds(const SkPaint& paint) {
     SkCanvas canvas;
+    uint32_t storage[kDrawLooperContextStorageLongCount];
 
-    this->init(&canvas);
+    SkDrawLooper::DrawContext* context =
+            this->init(&canvas, storage, sizeof(storage));
     for (;;) {
         SkPaint p(paint);
-        if (this->next(&canvas, &p)) {
+        if (context->next(&canvas, &p)) {
             p.setLooper(NULL);
             if (!p.canComputeFastBounds()) {
+                context->cleanup(storage);
                 return false;
             }
         } else {
             break;
         }
     }
+    context->cleanup(storage);
     return true;
 }
 
 void SkDrawLooper::computeFastBounds(const SkPaint& paint, const SkRect& src,
                                      SkRect* dst) {
     SkCanvas canvas;
+    uint32_t storage[kDrawLooperContextStorageLongCount];
 
     *dst = src;   // catch case where there are no loops
-    this->init(&canvas);
+    SkDrawLooper::DrawContext* context = this->init(
+            &canvas, storage, sizeof(storage));
     for (bool firstTime = true;; firstTime = false) {
         SkPaint p(paint);
-        if (this->next(&canvas, &p)) {
+        if (context->next(&canvas, &p)) {
             SkRect r(src);
 
             p.setLooper(NULL);
@@ -53,4 +59,13 @@ void SkDrawLooper::computeFastBounds(const SkPaint& paint, const SkRect& src,
             break;
         }
     }
+    context->cleanup(storage);
+}
+
+void SkDrawLooper::DrawContext::cleanup(void* storage) {
+    if ((void*)this == storage) {
+        this->~DrawContext();
+    } else {
+        SkDELETE(this);
+    }
 }