Part 1/3 (compositor) of adding with device scale factor to transport surfaces

cc/trees/layer_tree_host_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/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/json/json_writer.h"
@@ skipping 1187 matching lines @@
 
 void LayerTreeHostImpl::EnableVSyncNotification(bool enable) {
   if (output_surface_)
     output_surface_->EnableVSyncNotification(enable);
 }
 
 gfx::Size LayerTreeHostImpl::DeviceViewportSize() const {
   return device_viewport_size();
 }
 
+float LayerTreeHostImpl::DeviceScaleFactor() const {
+  return device_scale_factor_;
+}
+
 gfx::SizeF LayerTreeHostImpl::VisibleViewportSize() const {
   gfx::SizeF dip_size =
       gfx::ScaleSize(DeviceViewportSize(), 1.f / device_scale_factor());
 
   // The clip layer should be used if non-overlay scrollbars may exist since
   // it adjusts for them.
   LayerImpl* clip_layer = active_tree_->RootClipLayer();
   if (!Settings().solid_color_scrollbars && clip_layer &&
       clip_layer->masks_to_bounds())
     dip_size = clip_layer->bounds();
@@ skipping 285 matching lines @@
 
   UpdateMaxScrollOffset();
   SetFullRootLayerDamage();
 }
 
 void LayerTreeHostImpl::SetDeviceScaleFactor(float device_scale_factor) {
   if (device_scale_factor == device_scale_factor_)
     return;
   device_scale_factor_ = device_scale_factor;
 
+  if (renderer_)
+    renderer_->ViewportChanged();
+
   UpdateMaxScrollOffset();
   SetFullRootLayerDamage();
 }
 
 void LayerTreeHostImpl::UpdateMaxScrollOffset() {
   active_tree_->UpdateMaxScrollOffset();
 }
 
 void LayerTreeHostImpl::DidChangeTopControlsPosition() {
   client_->SetNeedsRedrawOnImplThread();
@@ skipping 712 matching lines @@
 }
 
 void LayerTreeHostImpl::SetDebugState(const LayerTreeDebugState& debug_state) {
   if (debug_state_.continuous_painting != debug_state.continuous_painting)
     paint_time_counter_->ClearHistory();
 
   debug_state_ = debug_state;
 }
 
 }  // namespace cc