Add a Display and ContextProvider concept to mojom, use to recreate

services/surfaces/surfaces_scheduler.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 "services/surfaces/surfaces_scheduler.h"
 
+#include "cc/surfaces/display.h"
+
 namespace surfaces {
 
-SurfacesScheduler::Client::~Client() {
-}
-
-SurfacesScheduler::SurfacesScheduler(Client* client) : client_(client) {
+SurfacesScheduler::SurfacesScheduler() {
   cc::SchedulerSettings settings;
   scheduler_ = cc::Scheduler::Create(
       this, settings, 0, base::MessageLoop::current()->task_runner(), nullptr,
       nullptr);
   scheduler_->SetCanStart();
   scheduler_->SetVisible(true);
   scheduler_->SetCanDraw(true);
   scheduler_->SetNeedsCommit();
 }
 
 SurfacesScheduler::~SurfacesScheduler() {
 }
 
 void SurfacesScheduler::SetNeedsDraw() {
   scheduler_->SetNeedsRedraw();
 }
 
 void SurfacesScheduler::OnVSyncParametersUpdated(base::TimeTicks timebase,
                                                  base::TimeDelta interval) {
   scheduler_->CommitVSyncParameters(timebase, interval);
 }
 
+void SurfacesScheduler::AddDisplay(cc::Display* display) {
+  DCHECK(displays_.find(display) == displays_.end());
+  displays_.insert(display);
+}
+
+void SurfacesScheduler::RemoveDisplay(cc::Display* display) {
+  auto it = displays_.find(display);
+  DCHECK(it != displays_.end());
+  displays_.erase(it);
+}
+
 void SurfacesScheduler::WillBeginImplFrame(const cc::BeginFrameArgs& args) {
 }
 
 void SurfacesScheduler::ScheduledActionSendBeginMainFrame() {
   scheduler_->NotifyBeginMainFrameStarted();
   scheduler_->NotifyReadyToCommit();
 }
 
 cc::DrawResult SurfacesScheduler::ScheduledActionDrawAndSwapIfPossible() {
   base::TimeTicks start = base::TimeTicks::Now();
-  client_->Draw();
+  for (const auto& it : displays_) {
+    it->Draw();
+  }
   base::TimeDelta duration = base::TimeTicks::Now() - start;
 
   draw_estimate_ = (duration + draw_estimate_) / 2;
   return cc::DRAW_SUCCESS;
 }
 
 cc::DrawResult SurfacesScheduler::ScheduledActionDrawAndSwapForced() {
   NOTREACHED() << "ScheduledActionDrawAndSwapIfPossible always succeeds.";
   return cc::DRAW_SUCCESS;
 }
@@ skipping 33 matching lines @@
 }
 
 void SurfacesScheduler::SendBeginFramesToChildren(
     const cc::BeginFrameArgs& args) {
 }
 
 void SurfacesScheduler::SendBeginMainFrameNotExpectedSoon() {
 }
 
 }  // namespace mojo