make allocPixels throw on failure

include/core/SkBitmap.h

Index: include/core/SkBitmap.h
diff --git a/include/core/SkBitmap.h b/include/core/SkBitmap.h
index 13a7e304c8b8c89c871fe404d84ccb936aff1209..c58c78d764da91da4eddb4435d5c96245cd52fa7 100644
--- a/include/core/SkBitmap.h
+++ b/include/core/SkBitmap.h
@@ -14,6 +14,16 @@
 #include "SkPoint.h"
 #include "SkRefCnt.h"
 
+#ifdef SK_SUPPORT_LEGACY_ALLOCPIXELS_BOOL
+    #define SK_ALLOCPIXELS_RETURN_TYPE  bool
+    #define SK_ALLOCPIXELS_RETURN_TRUE  return true
+    #define SK_ALLOCPIXELS_RETURN_FAIL  return false
+#else
+    #define SK_ALLOCPIXELS_RETURN_TYPE  void
+    #define SK_ALLOCPIXELS_RETURN_TRUE  return
+    #define SK_ALLOCPIXELS_RETURN_FAIL  sk_throw()
+#endif
+
 struct SkMask;
 struct SkIRect;
 struct SkRect;
@@ -218,7 +228,15 @@ public:
      *  a colortable, then ColorTable must be non-null, and will be ref'd.
      *  On failure, the bitmap will be set to empty and return false.
      */
-    bool allocPixels(const SkImageInfo&, SkPixelRefFactory*, SkColorTable*);
+    bool SK_WARN_UNUSED_RESULT tryAllocPixels(const SkImageInfo&, SkPixelRefFactory*, SkColorTable*);
+
+    SK_ALLOCPIXELS_RETURN_TYPE allocPixels(const SkImageInfo& info, SkPixelRefFactory* factory,
+                                           SkColorTable* ctable) {
+        if (!this->tryAllocPixels(info, factory, ctable)) {
+            SK_ALLOCPIXELS_RETURN_FAIL;
+        }
+        SK_ALLOCPIXELS_RETURN_TRUE;
+    }
 
     /**
      *  Allocate the bitmap's pixels to match the requested image info and
@@ -228,26 +246,39 @@ public:
      *  the pixel size specified by info.colorType()) then false is returned
      *  and the bitmap is set to empty.
      */
-    bool allocPixels(const SkImageInfo& info, size_t rowBytes);
+    bool SK_WARN_UNUSED_RESULT tryAllocPixels(const SkImageInfo& info, size_t rowBytes);
 
-    /**
-     *  Allocate a pixelref to match the specified image info, using the default
-     *  allocator.
-     *  On success, the bitmap's pixels will be "locked", and return true.
-     *  On failure, the bitmap will be set to empty and return false.
-     */
-    bool allocPixels(const SkImageInfo& info) {
+    SK_ALLOCPIXELS_RETURN_TYPE allocPixels(const SkImageInfo& info, size_t rowBytes) {
+        if (!this->tryAllocPixels(info, rowBytes)) {
+            SK_ALLOCPIXELS_RETURN_FAIL;
+        }
+        SK_ALLOCPIXELS_RETURN_TRUE;
+    }
+
+    bool SK_WARN_UNUSED_RESULT tryAllocPixels(const SkImageInfo& info) {
+        return this->tryAllocPixels(info, info.minRowBytes());
+    }
+
+    SK_ALLOCPIXELS_RETURN_TYPE allocPixels(const SkImageInfo& info) {
         return this->allocPixels(info, info.minRowBytes());
     }
 
-    bool allocN32Pixels(int width, int height, bool isOpaque = false) {
+    bool SK_WARN_UNUSED_RESULT tryAllocN32Pixels(int width, int height, bool isOpaque = false) {
+        SkImageInfo info = SkImageInfo::MakeN32Premul(width, height);
+        if (isOpaque) {
+            info.fAlphaType = kOpaque_SkAlphaType;
+        }
+        return this->tryAllocPixels(info);
+    }
+    
+    SK_ALLOCPIXELS_RETURN_TYPE allocN32Pixels(int width, int height, bool isOpaque = false) {
         SkImageInfo info = SkImageInfo::MakeN32Premul(width, height);
         if (isOpaque) {
             info.fAlphaType = kOpaque_SkAlphaType;
         }
         return this->allocPixels(info);
     }
-
+    
     /**
      *  Install a pixelref that wraps the specified pixels and rowBytes, and
      *  optional ReleaseProc and context. When the pixels are no longer
@@ -320,7 +351,11 @@ public:
         @return true if the allocation succeeds. If not the pixelref field of
                      the bitmap will be unchanged.
     */
-    bool allocPixels(SkColorTable* ctable = NULL) {
+    bool SK_WARN_UNUSED_RESULT tryAllocPixels(SkColorTable* ctable = NULL) {
+        return this->tryAllocPixels(NULL, ctable);
+    }
+
+    SK_ALLOCPIXELS_RETURN_TYPE allocPixels(SkColorTable* ctable = NULL) {
         return this->allocPixels(NULL, ctable);
     }
 
@@ -342,7 +377,14 @@ public:
         @return true if the allocation succeeds. If not the pixelref field of
                      the bitmap will be unchanged.
     */
-    bool allocPixels(Allocator* allocator, SkColorTable* ctable);
+    bool SK_WARN_UNUSED_RESULT tryAllocPixels(Allocator* allocator, SkColorTable* ctable);
+
+    SK_ALLOCPIXELS_RETURN_TYPE allocPixels(Allocator* allocator, SkColorTable* ctable) {
+        if (!this->tryAllocPixels(allocator, ctable)) {
+            SK_ALLOCPIXELS_RETURN_FAIL;
+        }
+        SK_ALLOCPIXELS_RETURN_TRUE;
+    }
 
     /**
      *  Return the current pixelref object or NULL if there is none. This does