[cc] Enable specifying a overhang/gutter texture.

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 2ee9f7590f8d5af00179f7488a0c8c0835047dcf..cb7df844a6d1de53328c91d0022abc81d18cb46e 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -436,6 +436,10 @@ void RenderWidgetCompositor::setHasTransparentBackground(bool transparent) {
   layer_tree_host_->set_has_transparent_background(transparent);
 }
 
+void RenderWidgetCompositor::setOverhangBitmap(const SkBitmap& bitmap) {
+  layer_tree_host_->SetOverhangBitmap(bitmap);
+}
+
 void RenderWidgetCompositor::setVisible(bool visible) {
   layer_tree_host_->SetVisible(visible);
 }