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

services/ui/ws/frame_generator_unittest.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 <memory>
 
 #include "base/test/test_message_loop.h"
 #include "cc/quads/render_pass.h"
@@ skipping 66 matching lines @@
   frame_generator_->DrawWindowTree(pass, root_window_.get(), gfx::Vector2d(),
                                    1.0f);
 }
 
 void FrameGeneratorTest::SetUp() {
   testing::Test::SetUp();
   frame_generator_delegate_ = base::MakeUnique<TestFrameGeneratorDelegate>();
   PlatformDisplayInitParams init_params;
   frame_generator_ = base::MakeUnique<FrameGenerator>(
       frame_generator_delegate_.get(), root_window_.get());
+  frame_generator_->set_device_scale_factor(
+      init_params.metrics.device_scale_factor);

[Fady Samuel, 2016/12/15 18:27:51]

I would actually make the device_scale_factor a param on the constructor.

[riajiang, 2016/12/15 19:01:43]

We are also updating DSF in PlatformDisplayDefault::UpdateViewportMetrics which
is calling this set_..., does it make sense to just have this one setter and use
this when initializing DSF as well?

   InitWindow(root_window());
 }
 
 void FrameGeneratorTest::TearDown() {
   frame_generator_.reset();
   frame_generator_delegate_.reset();
 }
 
 // Tests correctness of the SharedQuadStateList generated by
 // FrameGenerator::DrawWindowTree().
@@ skipping 38 matching lines @@
   EXPECT_EQ(3u, quad_state_list->size());
   auto it = quad_state_list->begin();
   EXPECT_EQ(child_opacity * root_opacity, (*it)->opacity);
   EXPECT_EQ(child_opacity * root_opacity, (*++it)->opacity);
   EXPECT_EQ(root_opacity, (*++it)->opacity);
 }
 
 }  // namespace test
 }  // namespace ws
 }  // namespace ui