Implement HiDPI and pinch-zoom scaling of filter params

cc/layers/render_surface_impl.cc

 // 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.
 
 #include "cc/layers/render_surface_impl.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
@@ skipping 208 matching lines @@
         uv_scale_y);
   }
 
   ResourceProvider::ResourceId mask_resource_id =
       mask_layer ? mask_layer->ContentsResourceId() : 0;
   gfx::Rect contents_changed_since_last_frame =
       ContentsChanged() ? content_rect_ : gfx::Rect();
 
   RenderPassDrawQuad* quad =
       render_pass->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
+  gfx::Transform owning_layer_to_target_scale;
+  owning_layer_to_target_scale.Scale(owning_layer_->contents_scale_x(),
+                                     owning_layer_->contents_scale_y());
+  owning_layer_to_target_scale.PreconcatTransform(

[enne (OOO), 2014/07/25 22:45:51]

Do you really need the full transform multiplication here? It seems like you
could do target_space_transform.Scale2d() and then scale by contents_scale_x/y?

[garykac, 2014/07/29 17:10:01]

Done.

+      owning_layer_->draw_properties().target_space_transform);
+  DCHECK(owning_layer_to_target_scale.IsScale2d());
   quad->SetNew(shared_quad_state,
                content_rect_,
                visible_content_rect,
                render_pass_id,
                for_replica,
                mask_resource_id,
                contents_changed_since_last_frame,
                mask_uv_rect,
                owning_layer_->filters(),
+               owning_layer_to_target_scale.Scale2d(),
                owning_layer_->background_filters());
 }
 
 }  // namespace cc