cc: Start using raster/eviction iterators.

cc/layers/picture_layer_impl.h

Index: cc/layers/picture_layer_impl.h
diff --git a/cc/layers/picture_layer_impl.h b/cc/layers/picture_layer_impl.h
index 7623c4da9e26bbf03dba98a1077870c5514f4c4c..1453adaa1a212a115a85d5cdd64c564f6990984a 100644
--- a/cc/layers/picture_layer_impl.h
+++ b/cc/layers/picture_layer_impl.h
@@ -128,6 +128,7 @@ class CC_EXPORT PictureLayerImpl
   virtual float GetSkewportTargetTimeInSeconds() const OVERRIDE;
   virtual int GetSkewportExtrapolationLimitInContentPixels() const OVERRIDE;
   virtual WhichTree GetTree() const OVERRIDE;
+  virtual bool RequiresHighResToDraw() const OVERRIDE;
 
   // PushPropertiesTo active tree => pending tree.
   void SyncTiling(const PictureLayerTiling* tiling);
@@ -165,13 +166,6 @@ class CC_EXPORT PictureLayerImpl
   float MinimumContentsScale() const;
   float SnappedContentsScale(float new_contents_scale);
   void ResetRasterScale();
-  void MarkVisibleResourcesAsRequired() const;
-  bool MarkVisibleTilesAsRequired(
-      PictureLayerTiling* tiling,
-      const PictureLayerTiling* optional_twin_tiling,
-      float contents_scale,
-      const gfx::Rect& rect,
-      const Region& missing_region) const;
 
   void DoPostCommitInitializationIfNeeded() {
     if (needs_post_commit_initialization_)