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

content/browser/compositor/gpu_process_transport_factory.cc

 // Copyright 2014 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 "content/browser/compositor/gpu_process_transport_factory.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 501 matching lines @@
                   begin_frame_source.get(), std::move(validator));
         } else {
 #if defined(USE_AURA)
           if (compositor->window()) {
             // TODO(mfomitchev): Remove this clause once we complete the switch
             // to Aura-Mus.
             display_output_surface =
                 base::MakeUnique<MusBrowserCompositorOutputSurface>(
                     compositor->window(), context_provider,
                     GetGpuMemoryBufferManager(), compositor->vsync_manager(),
-                    begin_frame_source.get(), std::move(validator));
+                    begin_frame_source.get(), std::move(validator),
+                    compositor->device_scale_factor());
           } else {
             aura::WindowTreeHost* host =
                 aura::WindowTreeHost::GetForAcceleratedWidget(
                     compositor->widget());
             display_output_surface =
                 base::MakeUnique<MusBrowserCompositorOutputSurface>(
                     host->window(), context_provider,
                     GetGpuMemoryBufferManager(), compositor->vsync_manager(),
-                    begin_frame_source.get(), std::move(validator));
+                    begin_frame_source.get(), std::move(validator),
+                    compositor->device_scale_factor());
           }
 #else
           NOTREACHED();
 #endif
         }
       }
     }
   }
 
   data->display_output_surface = display_output_surface.get();
@@ skipping 339 matching lines @@
       shared_vulkan_context_provider_ =
           cc::VulkanInProcessContextProvider::Create();
     }
 
     shared_vulkan_context_provider_initialized_ = true;
   }
   return shared_vulkan_context_provider_;
 }
 
 }  // namespace content