cc: Remove all remaining use of WebCore Rect/Point/Size types from the compositor.

cc/single_thread_proxy.cc

Index: cc/single_thread_proxy.cc
diff --git a/cc/single_thread_proxy.cc b/cc/single_thread_proxy.cc
index 7fe679ff5d4a0049f0e16918d0df183dc5d4cc09..b9cf3533ab7555821107295f051b1037a72fcd95 100644
--- a/cc/single_thread_proxy.cc
+++ b/cc/single_thread_proxy.cc
@@ -62,9 +62,9 @@ bool SingleThreadProxy::compositeAndReadback(void *pixels, const gfx::Rect& rect
     return true;
 }
 
-void SingleThreadProxy::startPageScaleAnimation(const IntSize& targetPosition, bool useAnchor, float scale, base::TimeDelta duration)
+void SingleThreadProxy::startPageScaleAnimation(gfx::Vector2d targetOffset, bool useAnchor, float scale, base::TimeDelta duration)
 {
-    m_layerTreeHostImpl->startPageScaleAnimation(targetPosition, useAnchor, scale, base::TimeTicks::Now(), duration);
+    m_layerTreeHostImpl->startPageScaleAnimation(targetOffset, useAnchor, scale, base::TimeTicks::Now(), duration);
 }
 
 void SingleThreadProxy::finishAllRendering()