cc: Stop using contents_scale_x() in PictureLayerImpl since it's 1.

cc/layers/picture_layer_impl.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYERS_PICTURE_LAYER_IMPL_H_
 #define CC_LAYERS_PICTURE_LAYER_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 154 matching lines @@
   virtual void RecalculateRasterScales();
   void CleanUpTilingsOnActiveLayer(
       std::vector<PictureLayerTiling*> used_tilings);
   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;
   gfx::Rect GetViewportForTilePriorityInContentSpace() const;
   PictureLayerImpl* GetRecycledTwinLayer();
 
   void DoPostCommitInitializationIfNeeded() {
     if (needs_post_commit_initialization_)
       DoPostCommitInitialization();
   }
   void DoPostCommitInitialization();
@@ skipping 43 matching lines @@
   gfx::Rect viewport_rect_for_tile_priority_;
   gfx::Transform screen_space_transform_for_tile_priority_;
 
   friend class PictureLayer;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_IMPL_H_