Make PageScaleFactor work for oopif subframes.

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 3bc288d69076af5e7f72ae722f9eda75cf369b4b..02fd36a9923f5af91e342c88e66e4d4a7da15c83 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -704,6 +704,14 @@ void RenderWidgetCompositor::setVisible(bool visible) {
   layer_tree_host_->SetVisible(visible);
 }
 
+float RenderWidgetCompositor::pageScaleFactor() {
+  return layer_tree_host()->GetLayerTree()->page_scale_factor();
+}
+
+void RenderWidgetCompositor::SetPageScaleFactorForSubframe(float scale) {
+  layer_tree_host()->GetLayerTree()->SetSubframePageScaleFactor(scale);
+}
+
 void RenderWidgetCompositor::setPageScaleFactorAndLimits(
     float page_scale_factor, float minimum, float maximum) {
   layer_tree_host_->GetLayerTree()->SetPageScaleFactorAndLimits(