Make PageScaleFactor work for oopif subframes.

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 24e4f8aff879c80c6f1c748b83c73318cb22aa56..d105006616a738a06cbfb174ce7fbcde6f0ca907 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -59,10 +59,12 @@ class CC_EXPORT LayerTreeImpl {
   // This is the number of times a fixed point has to be hit continuously by a
   // layer to consider it as jittering.
   enum : int { kFixedPointHitsThreshold = 3 };
-  LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl,
-                scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor,
-                scoped_refptr<SyncedBrowserControls> top_controls_shown_ratio,
-                scoped_refptr<SyncedElasticOverscroll> elastic_overscroll);
+  LayerTreeImpl(
+      LayerTreeHostImpl* layer_tree_host_impl,
+      scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor,
+      scoped_refptr<SyncedProperty<ScaleGroup>> subframe_page_scale_factor,
+      scoped_refptr<SyncedBrowserControls> top_controls_shown_ratio,
+      scoped_refptr<SyncedElasticOverscroll> elastic_overscroll);
   virtual ~LayerTreeImpl();
 
   void Shutdown();
@@ -204,12 +206,20 @@ class CC_EXPORT LayerTreeImpl {
 
   void UpdatePropertyTreeScrollingAndAnimationFromMainThread();
   void SetPageScaleOnActiveTree(float active_page_scale);
+  void SetSubframePageScaleOnActiveTree(float active_subframe_page_scale);
   void PushPageScaleFromMainThread(float page_scale_factor,
                                    float min_page_scale_factor,
                                    float max_page_scale_factor);
+  void PushPageScaleFromMainThread(float page_scale_factor,
+                                   float subframe_page_scale_factor,
+                                   float min_page_scale_factor,
+                                   float max_page_scale_factor);
   float current_page_scale_factor() const {
     return page_scale_factor()->Current(IsActiveTree());
   }
+  float GetSubframePageScaleFactor() const {
+    return subframe_page_scale_factor()->Current(IsActiveTree());
+  }
   float min_page_scale_factor() const { return min_page_scale_factor_; }
   float max_page_scale_factor() const { return max_page_scale_factor_; }
 
@@ -218,6 +228,9 @@ class CC_EXPORT LayerTreeImpl {
   SyncedProperty<ScaleGroup>* page_scale_factor();
   const SyncedProperty<ScaleGroup>* page_scale_factor() const;
 
+  SyncedProperty<ScaleGroup>* subframe_page_scale_factor();
+  const SyncedProperty<ScaleGroup>* subframe_page_scale_factor() const;
+
   void SetDeviceScaleFactor(float device_scale_factor);
   float device_scale_factor() const { return device_scale_factor_; }
 
@@ -459,6 +472,7 @@ class CC_EXPORT LayerTreeImpl {
  protected:
   float ClampPageScaleFactorToLimits(float page_scale_factor) const;
   void PushPageScaleFactorAndLimits(const float* page_scale_factor,
+                                    const float* subframe_page_scale_factor,
                                     float min_page_scale_factor,
                                     float max_page_scale_factor);
   bool SetPageScaleFactorLimits(float min_page_scale_factor,
@@ -487,6 +501,7 @@ class CC_EXPORT LayerTreeImpl {
   LayerSelection selection_;
 
   scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor_;
+  scoped_refptr<SyncedProperty<ScaleGroup>> subframe_page_scale_factor_;
   float min_page_scale_factor_;
   float max_page_scale_factor_;