Plumb physical backing size from RWHV to renderer CC.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 9597b4b4be03110049cc2ccdf174544cfdef69c4..2a91ec767ac1d04e17ccaebd661249394cafa9f1 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -5415,7 +5415,8 @@ void RenderViewImpl::OnDisableAutoResize(const gfx::Size& new_size) {
     return;
   webview()->disableAutoResizeMode();
 
-  Resize(new_size, resizer_rect_, is_fullscreen_, NO_RESIZE_ACK);
+  Resize(new_size, physical_backing_size_, resizer_rect_, is_fullscreen_,
+         NO_RESIZE_ACK);
 }
 
 void RenderViewImpl::OnEnablePreferredSizeChangedMode() {
@@ -5710,6 +5711,7 @@ void RenderViewImpl::OnMoveOrResizeStarted() {
 }
 
 void RenderViewImpl::OnResize(const gfx::Size& new_size,
+                              const gfx::Size& physical_backing_size,
                               const gfx::Rect& resizer_rect,
                               bool is_fullscreen) {
   if (webview()) {
@@ -5721,7 +5723,8 @@ void RenderViewImpl::OnResize(const gfx::Size& new_size,
     UpdateScrollState(webview()->mainFrame());
   }
 
-  RenderWidget::OnResize(new_size, resizer_rect, is_fullscreen);
+  RenderWidget::OnResize(new_size, physical_backing_size, resizer_rect,
+                         is_fullscreen);
 }
 
 void RenderViewImpl::WillInitiatePaint() {