Implement HiDPI and pinch-zoom scaling of filter params

cc/quads/render_pass_draw_quad.h

 // Copyright 2011 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_QUADS_RENDER_PASS_DRAW_QUAD_H_
 #define CC_QUADS_RENDER_PASS_DRAW_QUAD_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
@@ skipping 11 matching lines @@
 
   void SetNew(const SharedQuadState* shared_quad_state,
               const gfx::Rect& rect,
               const gfx::Rect& visible_rect,
               RenderPass::Id render_pass_id,
               bool is_replica,
               ResourceProvider::ResourceId mask_resource_id,
               const gfx::Rect& contents_changed_since_last_frame,
               const gfx::RectF& mask_uv_rect,
               const FilterOperations& filters,
+              const gfx::Vector2dF& filters_scale,
               const FilterOperations& background_filters);
 
   void SetAll(const SharedQuadState* shared_quad_state,
               const gfx::Rect& rect,
               const gfx::Rect& opaque_rect,
               const gfx::Rect& visible_rect,
               bool needs_blending,
               RenderPass::Id render_pass_id,
               bool is_replica,
               ResourceProvider::ResourceId mask_resource_id,
               const gfx::Rect& contents_changed_since_last_frame,
               const gfx::RectF& mask_uv_rect,
               const FilterOperations& filters,
+              const gfx::Vector2dF& filters_scale,
               const FilterOperations& background_filters);
 
   RenderPass::Id render_pass_id;
   bool is_replica;
   ResourceProvider::ResourceId mask_resource_id;
   gfx::Rect contents_changed_since_last_frame;
   gfx::RectF mask_uv_rect;
 
   // Post-processing filters, applied to the pixels in the render pass' texture.
   FilterOperations filters;
 
+  // The scale from layer space of the root layer of the render pass to
+  // the render pass physical pixels. This scale is applied to the filter
+  // parameters for pixel-moving filters. This scale should include
+  // content-to-target-space scale, and device pixel ratio.
+  gfx::Vector2dF filters_scale;
+
   // Post-processing filters, applied to the pixels showing through the
   // background of the render pass, from behind it.
   FilterOperations background_filters;
 
   virtual void IterateResources(const ResourceIteratorCallback& callback)
       OVERRIDE;
 
   static const RenderPassDrawQuad* MaterialCast(const DrawQuad*);
 
  private:
   virtual void ExtendValue(base::debug::TracedValue* value) const OVERRIDE;
 };
 
 }  // namespace cc
 
 #endif  // CC_QUADS_RENDER_PASS_DRAW_QUAD_H_