CompositingReasonFinder should use a virtual function instead of a nest of branches

Source/core/page/ChromeClient.h

Index: Source/core/page/ChromeClient.h
diff --git a/Source/core/page/ChromeClient.h b/Source/core/page/ChromeClient.h
index 5414cd5099c1823d93a6e4007b8693ea99edce86..44b5e9eaad07a78dddfa737a1c9c5ac614a5118a 100644
--- a/Source/core/page/ChromeClient.h
+++ b/Source/core/page/ChromeClient.h
@@ -29,6 +29,7 @@
 #include "core/frame/ConsoleTypes.h"
 #include "core/page/FocusType.h"
 #include "core/rendering/RenderEmbeddedObject.h"
+#include "core/rendering/compositing/CompositingTriggers.h"
 #include "core/rendering/style/RenderStyleConstants.h"
 #include "platform/Cursor.h"
 #include "platform/HostWindow.h"
@@ -192,20 +193,8 @@ public:
     // Pass 0 as the GraphicsLayer to detatch the root layer.
     virtual void attachRootGraphicsLayer(GraphicsLayer*) = 0;
 
-    enum CompositingTrigger {
-        ThreeDTransformTrigger = 1 << 0,
-        VideoTrigger = 1 << 1,
-        PluginTrigger = 1 << 2,
-        CanvasTrigger = 1 << 3,
-        AnimationTrigger = 1 << 4,
-        FilterTrigger = 1 << 5,
-        ScrollableInnerFrameTrigger = 1 << 6,
-        AllTriggers = 0xFFFFFFFF
-    };
-    typedef unsigned CompositingTriggerFlags;
-
     // Returns a bitfield indicating conditions that can trigger the compositor.
-    virtual CompositingTriggerFlags allowedCompositingTriggers() const { return static_cast<CompositingTriggerFlags>(AllTriggers); }
+    virtual CompositingTriggerFlags allowedCompositingTriggers() const { return static_cast<CompositingTriggerFlags>(AllCompositingTriggers); }
 
     virtual void enterFullScreenForElement(Element*) { }
     virtual void exitFullScreenForElement(Element*) { }