color: Add NSScreenColorSpaceDidChangeNotification observer

content/browser/renderer_host/browser_compositor_view_mac.mm

 // 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/renderer_host/browser_compositor_view_mac.h"
 
 #include <stdint.h>
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/compositor/image_transport_factory.h"
 #include "content/browser/renderer_host/compositor_resize_lock.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/context_factory.h"
 #include "media/base/video_frame.h"
 #include "ui/accelerated_widget_mac/accelerated_widget_mac.h"
 #include "ui/accelerated_widget_mac/window_resize_helper_mac.h"
 #include "ui/base/layout.h"
+#include "ui/display/screen.h"
 #include "ui/gfx/geometry/dip_util.h"
 
 namespace content {
 
 namespace {
 
 // Set when no browser compositors should remain alive.
 bool g_has_shut_down = false;
 
 // The number of placeholder objects allocated. If this reaches zero, then
@@ skipping 318 matching lines @@
         has_transparent_background_);
     recyclable_compositor_->accelerated_widget_mac()->SetNSView(
         accelerated_widget_mac_ns_view_);
     state_ = HasDetachedCompositor;
   }
 
   // Transition HasDetachedCompositor -> HasAttachedCompositor.
   if (state_ == HasDetachedCompositor && new_state == HasAttachedCompositor) {
     NSView* ns_view =
         accelerated_widget_mac_ns_view_->AcceleratedWidgetGetNSView();
-    float scale_factor = ui::GetScaleFactorForNativeView(ns_view);

[ccameron, 2017/06/26 22:45:02]

At the moment, ui::GetScaleFactorForNativeView wraps
display::Screen::GetScreen()->GetDisplayNearestView on all platforms but Mac. I
plan to make this call uniform on all platforms.

+    display::Display display =
+        display::Screen::GetScreen()->GetDisplayNearestView(ns_view);
     NSSize dip_ns_size = [ns_view bounds].size;
-    gfx::Size pixel_size(dip_ns_size.width * scale_factor,
-                         dip_ns_size.height * scale_factor);
+    gfx::Size pixel_size(dip_ns_size.width * display.device_scale_factor(),
+                         dip_ns_size.height * display.device_scale_factor());
 
     delegated_frame_host_->SetCompositor(recyclable_compositor_->compositor());
     delegated_frame_host_->WasShown(ui::LatencyInfo());
     // Unsuspend the browser compositor after showing the delegated frame host.
     // If there is not a saved delegated frame, then the delegated frame host
     // will keep the compositor locked until a delegated frame is swapped.
-    recyclable_compositor_->compositor()->SetScaleAndSize(scale_factor,
-                                                          pixel_size);
+    recyclable_compositor_->compositor()->SetDisplayColorSpace(
+        display.color_space());
+    recyclable_compositor_->compositor()->SetScaleAndSize(
+        display.device_scale_factor(), pixel_size);
     recyclable_compositor_->Unsuspend();
     state_ = HasAttachedCompositor;
   }
 
   // Transition HasAttachedCompositor -> HasDetachedCompositor.
   if (state_ == HasAttachedCompositor && new_state != HasAttachedCompositor) {
     // Ensure that any changes made to the ui::Compositor do not result in new
     // frames being produced.
     recyclable_compositor_->Suspend();
     // Marking the DelegatedFrameHost as removed from the window hierarchy is
@@ skipping 58 matching lines @@
 void BrowserCompositorMac::OnBeginFrame() {
   client_->BrowserCompositorMacOnBeginFrame();
 }
 
 bool BrowserCompositorMac::IsAutoResizeEnabled() const {
   NOTREACHED();
   return false;
 }
 
 }  // namespace content