Set device scale factor in CompositorFrame and scale frame size in WS.

services/ui/ws/frame_generator.cc

 // Copyright 2016 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 "services/ui/ws/frame_generator.h"
 
 #include "base/containers/adapters.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/quads/render_pass.h"
 #include "cc/quads/render_pass_draw_quad.h"
 #include "cc/quads/shared_quad_state.h"
 #include "cc/quads/surface_draw_quad.h"
 #include "cc/surfaces/surface_id.h"
 #include "services/ui/ws/frame_generator_delegate.h"
 #include "services/ui/ws/server_window.h"
 #include "services/ui/ws/server_window_compositor_frame_sink_manager.h"
 #include "services/ui/ws/server_window_delegate.h"
 
 namespace ui {
 
 namespace ws {
 
 FrameGenerator::FrameGenerator(FrameGeneratorDelegate* delegate,
-                               ServerWindow* root_window)
+                               ServerWindow* root_window,
+                               float device_scale_factor)
     : delegate_(delegate),
       root_window_(root_window),
+      device_scale_factor_(device_scale_factor),
       top_level_root_surface_id_(
           cc::FrameSinkId(0, 0),
           cc::LocalFrameId(0, base::UnguessableToken::Create())),
       binding_(this),
       weak_factory_(this) {
   DCHECK(delegate_);
 }
 
 FrameGenerator::~FrameGenerator() {
   RemoveDeadSurfaceReferences();
@@ skipping 48 matching lines @@
     AddNewParentReferences(ref.child_id, surface_id);
 
   // Move the existing reference to list of references to remove after we submit
   // the next CompositorFrame. Update local reference cache to be the new
   // reference. If this is the display root surface then removing this reference
   // will recursively remove any references it held.
   dead_references_.push_back(ref);
   ref.child_id = surface_id;
 }
 
+void FrameGenerator::UpdateDeviceScaleFactor(float device_scale_factor) {

[sky, 2016/12/03 16:28:30]

Generally for trivial functions like this we use unix_hacker_case and inline it
in the header, e.g.:
void set_device_scale_factor(...) ...

[riajiang, 2016/12/09 19:31:44]

Done.

+  device_scale_factor_ = device_scale_factor;
+}
+
 void FrameGenerator::DidReceiveCompositorFrameAck() {}
 
 void FrameGenerator::OnBeginFrame(const cc::BeginFrameArgs& begin_frame_arags) {
   if (!root_window_->visible())
     return;
 
   // TODO(fsamuel): We should add a trace for generating a top level frame.
   cc::CompositorFrame frame(GenerateCompositorFrame(root_window_->bounds()));
 
   if (compositor_frame_sink_) {
@@ skipping 43 matching lines @@
     cc::FilterOperations filters;
     filters.Append(cc::FilterOperation::CreateInvertFilter(1.f));
     quad->SetNew(shared_state, output_rect, output_rect, render_pass_id,
                  0 /* mask_resource_id */, gfx::Vector2dF() /* mask_uv_scale */,
                  gfx::Size() /* mask_texture_size */, filters,
                  gfx::Vector2dF() /* filters_scale */,
                  gfx::PointF() /* filters_origin */,
                  cc::FilterOperations() /* background_filters */);
     frame.render_pass_list.push_back(std::move(invert_pass));
   }
+  frame.metadata.device_scale_factor = device_scale_factor_;
 
   return frame;
 }
 
 void FrameGenerator::DrawWindowTree(
     cc::RenderPass* pass,
     ServerWindow* window,
     const gfx::Vector2d& parent_to_root_origin_offset,
     float opacity) {
   if (!window->visible())
@@ skipping 185 matching lines @@
   cc::SurfaceId underlay_surface_id =
       window->compositor_frame_sink_manager()->GetLatestSurfaceId(
           mojom::CompositorFrameSinkType::UNDERLAY);
   if (underlay_surface_id.is_valid())
     RemoveFrameSinkReference(underlay_surface_id.frame_sink_id());
 }
 
 }  // namespace ws
 
 }  // namespace ui