Phase II Step 1: Remove updateImage() reentrancy around decodeError()

third_party/WebKit/Source/core/loader/resource/ImageResourceContent.h

Index: third_party/WebKit/Source/core/loader/resource/ImageResourceContent.h
diff --git a/third_party/WebKit/Source/core/loader/resource/ImageResourceContent.h b/third_party/WebKit/Source/core/loader/resource/ImageResourceContent.h
index af9c6fe70e2a7d0ac2576219a60747e4c02ee631..9d6417aebcf6c3fc086ed036a04aa9621fb8df54 100644
--- a/third_party/WebKit/Source/core/loader/resource/ImageResourceContent.h
+++ b/third_party/WebKit/Source/core/loader/resource/ImageResourceContent.h
@@ -132,9 +132,16 @@ class CORE_EXPORT ImageResourceContent final
     // Clears the image and always notifies observers (without updating).
     ClearImageAndNotifyObservers,
   };
-  void updateImage(PassRefPtr<SharedBuffer>,
-                   UpdateImageOption,
-                   bool allDataReceived);
+  enum class UpdateImageResult {
+    NoDecodeError,
+
+    // Decode error occurred. Observers are not notified.
+    // Only occurs when UpdateImage or ClearAndUpdateImage is specified.
+    ShouldDecodeError,
+  };
+  WARN_UNUSED_RESULT UpdateImageResult updateImage(PassRefPtr<SharedBuffer>,
+                                                   UpdateImageOption,
+                                                   bool allDataReceived);
 
   void destroyDecodedData();
   void doResetAnimation();
@@ -181,6 +188,10 @@ class CORE_EXPORT ImageResourceContent final
   // Indicates if this resource's encoded image data can be purged and refetched
   // from disk cache to save memory usage. See crbug/664437.
   bool m_isRefetchableDataFromDiskCache;
+
+#if DCHECK_IS_ON()
+  bool m_isUpdateImageBeingCalled = false;
+#endif
 };
 
 }  // namespace blink