[Sanity Review] cc: Mark an event has not-handled if it didn't cause a scroll

Source/Platform/chromium/public/WebInputHandlerClient.h

 /* Copyright (C) 2012 Google Inc. All rights reserved.
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@@ skipping 35 matching lines @@
     // Returns ScrollStarted if the layer at the coordinates can be scrolled,
     // ScrollOnMainThread if the scroll event should instead be delegated to the
     // main thread, or ScrollIgnored if there is nothing to be scrolled at the
     // given coordinates.
     virtual ScrollStatus scrollBegin(WebPoint, ScrollInputType) = 0;
 
     // Scroll the selected layer starting at the given window coordinate. If
     // there is no room to move the layer in the requested direction, its first
     // ancestor layer that can be scrolled will be moved instead. Should only be
     // called if scrollBegin() returned ScrollStarted.
-    virtual void scrollBy(WebPoint, WebSize) = 0;
+    virtual bool scrollBy(WebPoint, WebSize) = 0;

[danakj, 2012/11/14 01:55:32]

You should add a comment about the return value.

Is a bool always going to be enough? Should you maybe return the WebSize
remaining of what was not scrolled (say you scroll to the bottom of the page mid
scroll?)

See similar code for the pageScaleViewport in layer_tree_host_impl for a
precedent. That's why I thought of it.

[rjkroege, 2012/11/14 17:00:26]

And: it would be nice to use enums for these sorts of things because (at least
I) can't remember what processed means. :-)

 
     // Stop scrolling the selected layer. Should only be called if scrollBegin()
     // returned ScrollStarted.
     virtual void scrollEnd() = 0;
 
     virtual void pinchGestureBegin() = 0;
     virtual void pinchGestureUpdate(float magnifyDelta, WebPoint anchor) = 0;
     virtual void pinchGestureEnd() = 0;
 
     virtual void startPageScaleAnimation(WebSize targetPosition,
                                          bool anchorPoint,
                                          float pageScale,
                                          double startTime,
                                          double duration) = 0;
 
     // Request another callback to WebInputHandler::animate().
     virtual void scheduleAnimation() = 0;
 
 protected:
     virtual ~WebInputHandlerClient() { }
 };
 
 }
 
 #endif