Merge clearImage() and clearImageAndNotifyObservers() into updateImage()

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ImageResourceContent_h
 #define ImageResourceContent_h
 
 #include "core/CoreExport.h"
 #include "core/fetch/ResourceStatus.h"
 #include "platform/geometry/IntRect.h"
@@ skipping 95 matching lines @@
   bool hasCacheControlNoStoreHeader() const;
 
   void emulateLoadStartedForInspector(ResourceFetcher*,
                                       const KURL&,
                                       const AtomicString& initiatorName);
 
   void setNotRefetchableDataFromDiskCache() {
     m_isRefetchableDataFromDiskCache = false;
   }
 
-  // For ImageResource only.
-  void setImageResourceInfo(ImageResourceInfo*);
-  enum ClearImageOption { ClearExistingImage, KeepExistingImage };
+  // The following public methods should be called from ImageResource only.
+
+  // updateImage() is the single control point of image content modification
+  // from ImageResource that all image updates should call.
+  // We clear and/or update images in this single method
+  // (controlled by UpdateImageOption) rather than providing separate methods,
+  // in order to centralize state changes and
+  // not to expose the state inbetween to ImageResource.
+  enum UpdateImageOption {
+    // Updates the image (including placeholder and decode error handling
+    // and notifying observers) if needed.
+    UpdateImage,
+
+    // Clears the image and then updates the image if needed.
+    ClearAndUpdateImage,
+
+    // Clears the image and always notifies observers (without updating).
+    ClearImageAndNotifyObservers,
+  };
   void updateImage(PassRefPtr<SharedBuffer>,
-                   ClearImageOption,
+                   UpdateImageOption,
                    bool allDataReceived);
-  enum NotifyFinishOption { ShouldNotifyFinish, DoNotNotifyFinish };
-  void clearImage();
-  void clearImageAndNotifyObservers(NotifyFinishOption);
-  ResourcePriority priorityFromObservers() const;
+
   void destroyDecodedData();
   void doResetAnimation();
+
+  void setImageResourceInfo(ImageResourceInfo*);
+
+  ResourcePriority priorityFromObservers() const;
   PassRefPtr<const SharedBuffer> resourceBuffer() const;
   bool shouldUpdateImageImmediately() const;
   bool hasObservers() const {
     return !m_observers.isEmpty() || !m_finishedObservers.isEmpty();
   }
   bool isRefetchableDataFromDiskCache() const {
     return m_isRefetchableDataFromDiskCache;
   }
 
  private:
   explicit ImageResourceContent(PassRefPtr<blink::Image> = nullptr);
 
   // ImageObserver
   void decodedSizeChangedTo(const blink::Image*, size_t newSize) override;
   bool shouldPauseAnimation(const blink::Image*) override;
   void animationAdvanced(const blink::Image*) override;
   void changedInRect(const blink::Image*, const IntRect&) override;
 
   PassRefPtr<Image> createImage();
+  void clearImage();
+
+  enum NotifyFinishOption { ShouldNotifyFinish, DoNotNotifyFinish };
 
   // If not null, changeRect is the changed part of the image.
   void notifyObservers(NotifyFinishOption, const IntRect* changeRect = nullptr);
   void markObserverFinished(ImageResourceObserver*);
 
   Member<ImageResourceInfo> m_info;
 
   RefPtr<blink::Image> m_image;
 
   HashCountedSet<ImageResourceObserver*> m_observers;
   HashCountedSet<ImageResourceObserver*> m_finishedObservers;
 
   Image::SizeAvailability m_sizeAvailable = Image::SizeUnavailable;
 
   // 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;
 };
 
 }  // namespace blink
 
 #endif