Don't use a low-quality filter when painting images while others are animating.

third_party/WebKit/Source/core/layout/ImageQualityController.h

Index: third_party/WebKit/Source/core/layout/ImageQualityController.h
diff --git a/third_party/WebKit/Source/core/layout/ImageQualityController.h b/third_party/WebKit/Source/core/layout/ImageQualityController.h
index 328750184526563b1bc0bbd0efdf3d8ae92fcd85..64b876cf42a1837e549788b82db5ae6bcf4b525b 100644
--- a/third_party/WebKit/Source/core/layout/ImageQualityController.h
+++ b/third_party/WebKit/Source/core/layout/ImageQualityController.h
@@ -44,7 +44,13 @@
 namespace blink {
 
 typedef HashMap<const void*, LayoutSize> LayerSizeMap;
-typedef HashMap<const LayoutObject*, LayerSizeMap> ObjectLayerSizeMap;
+
+struct ObjectResizeInfo {
+    LayerSizeMap layerSizeMap;
+    bool isResizing;
+};
+
+typedef HashMap<const LayoutObject*, ObjectResizeInfo> ObjectLayerSizeMap;
 
 class CORE_EXPORT ImageQualityController final {
     WTF_MAKE_NONCOPYABLE(ImageQualityController); USING_FAST_MALLOC(ImageQualityController);
@@ -61,7 +67,7 @@ private:
     ImageQualityController();
 
     static bool has(const LayoutObject&);
-    void set(const LayoutObject&, LayerSizeMap* innerMap, const void* layer, const LayoutSize&);
+    void set(const LayoutObject&, LayerSizeMap* innerMap, const void* layer, const LayoutSize&, bool isResizing);
 
     bool shouldPaintAtLowQuality(const LayoutObject&, Image*, const void* layer, const LayoutSize&);
     void removeLayer(const LayoutObject&, LayerSizeMap* innerMap, const void* layer);
@@ -76,7 +82,6 @@ private:
 
     ObjectLayerSizeMap m_objectLayerSizeMap;
     OwnPtr<Timer<ImageQualityController>> m_timer;
-    bool m_animatedResizeIsActive;
     bool m_liveResizeOptimizationIsActive;
 
     // For calling set().
@@ -85,6 +90,7 @@ private:
     // For calling setTimer(),
     FRIEND_TEST_ALL_PREFIXES(ImageQualityControllerTest, LowQualityFilterForLiveResize);
     FRIEND_TEST_ALL_PREFIXES(ImageQualityControllerTest, LowQualityFilterForResizingImage);
+    FRIEND_TEST_ALL_PREFIXES(ImageQualityControllerTest, MediumQualityFilterForNotAnimatedWhileAnotherAnimates);
     FRIEND_TEST_ALL_PREFIXES(ImageQualityControllerTest, DontKickTheAnimationTimerWhenPaintingAtTheSameSize);
 };