Remove FrameGenerator::root_window_

services/ui/ws/platform_display_default.cc

Index: services/ui/ws/platform_display_default.cc
diff --git a/services/ui/ws/platform_display_default.cc b/services/ui/ws/platform_display_default.cc
index a126d699c0df820a8eb3ad71a2dd2ebf75ed8794..ea7c9a26c5107cbedbfa111330ca16cb9bba5276 100644
--- a/services/ui/ws/platform_display_default.cc
+++ b/services/ui/ws/platform_display_default.cc
@@ -37,8 +37,7 @@ PlatformDisplayDefault::PlatformDisplayDefault(
       image_cursors_(new ImageCursors),
 #endif
       metrics_(metrics),
-      widget_(gfx::kNullAcceleratedWidget),
-      init_device_scale_factor_(metrics.device_scale_factor) {
+      widget_(gfx::kNullAcceleratedWidget) {
 }
 
 PlatformDisplayDefault::~PlatformDisplayDefault() {
@@ -134,6 +133,8 @@ bool PlatformDisplayDefault::UpdateViewportMetrics(
   if (bounds.size() != metrics.bounds_in_pixels.size()) {
     bounds.set_size(metrics.bounds_in_pixels.size());
     platform_window_->SetBounds(bounds);
+    if (frame_generator_)
+      frame_generator_->OnWindowBoundsChanged(bounds);
   }
 
   metrics_ = metrics;
@@ -257,8 +258,9 @@ void PlatformDisplayDefault::OnAcceleratedWidgetAvailable(
           std::move(display_private),
           std::move(compositor_frame_sink_client_request));
   frame_generator_ = base::MakeUnique<FrameGenerator>(
-      root_window_, std::move(display_client_compositor_frame_sink));
-  frame_generator_->SetDeviceScaleFactor(init_device_scale_factor_);
+      std::move(display_client_compositor_frame_sink));
+  frame_generator_->OnWindowBoundsChanged(root_window_->bounds());
+  frame_generator_->SetDeviceScaleFactor(metrics_.device_scale_factor);
 }
 
 void PlatformDisplayDefault::OnAcceleratedWidgetDestroyed() {