aura: Allow platform to choose how it retrieves ICCProfile.

ui/aura/window_tree_host.cc

Index: ui/aura/window_tree_host.cc
diff --git a/ui/aura/window_tree_host.cc b/ui/aura/window_tree_host.cc
index 902d8e94569e13608320f59b23f0c89ac1f39f9e..fc2800f32c4ecdb524945720ed872b3ae7cc35cc 100644
--- a/ui/aura/window_tree_host.cc
+++ b/ui/aura/window_tree_host.cc
@@ -69,11 +69,8 @@ void WindowTreeHost::InitCompositor() {
   compositor_->SetScaleAndSize(GetDeviceScaleFactorFromDisplay(window()),
                                GetBounds().size());
   compositor_->SetRootLayer(window()->layer());
-
-  // TODO(hubbe): Get the color space from the *current* monitor and
-  // update it when window is moved or color space configuration changes.
   compositor_->SetDisplayColorSpace(
-      gfx::ICCProfile::FromBestMonitor().GetColorSpace());
+      GetICCProfileForCurrentDisplay().GetColorSpace());
 }
 
 void WindowTreeHost::AddObserver(WindowTreeHostObserver* observer) {
@@ -320,6 +317,12 @@ ui::EventProcessor* WindowTreeHost::GetEventProcessor() {
 ////////////////////////////////////////////////////////////////////////////////
 // WindowTreeHost, private:
 
+gfx::ICCProfile WindowTreeHost::GetICCProfileForCurrentDisplay() {
+  // TODO(hubbe): Get the color space from the *current* monitor and
+  // update it when window is moved or color space configuration changes.
+  return gfx::ICCProfile::FromBestMonitor();
+}
+
 void WindowTreeHost::MoveCursorToInternal(const gfx::Point& root_location,
                                           const gfx::Point& host_location) {
   last_cursor_request_position_in_host_ = host_location;