Replace overdraw_bottom_height with top_controls_layout_height.

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index 80f05962c149e65066cb7118baa85b1d92260568..2c80fbd3780e88c43e1f7a6cc584acfda90c7259 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -723,9 +723,9 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   // The size of the view's backing surface in non-DPI-adjusted pixels.
   gfx::Size physical_backing_size_;
 
-  // The height of the physical backing surface that is overdrawn opaquely in
-  // the browser, for example by an on-screen-keyboard (in DPI-adjusted pixels).
-  float overdraw_bottom_height_;
+  // The amount that the viewport size given to Blink was shrunk by the URL-bar
+  // (always 0 on platforms where URL-bar hiding isn't supported).
+  float top_controls_layout_height_;
 
   // The size of the visible viewport, which may be smaller than the view if the
   // view is partially occluded (e.g. by a virtual keyboard).  The size is in