[Reland] Per WebViewScheduler virtual time

components/scheduler/renderer/web_view_scheduler_impl.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_SCHEDULER_RENDERER_WEB_VIEW_SCHEDULER_IMPL_H_
 #define COMPONENTS_SCHEDULER_RENDERER_WEB_VIEW_SCHEDULER_IMPL_H_
 
 #include <set>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/scheduler/scheduler_export.h"
 #include "third_party/WebKit/public/platform/WebViewScheduler.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace blink {
 class WebView;
 }  // namespace blink
 
 namespace scheduler {
 
+class AutoAdvancingVirtualTimeDomain;
 class RendererSchedulerImpl;
 class WebFrameSchedulerImpl;
 
 class SCHEDULER_EXPORT WebViewSchedulerImpl : public blink::WebViewScheduler {
  public:
   WebViewSchedulerImpl(blink::WebView* web_view,
                        RendererSchedulerImpl* renderer_scheduler,
                        bool disable_background_timer_throttling);
 
   ~WebViewSchedulerImpl() override;
 
   // blink::WebViewScheduler implementation:
   void setPageVisible(bool page_visible) override;
   blink::WebPassOwnPtr<blink::WebFrameScheduler> createFrameScheduler()
       override;
+  void useVirtualTime() override;

[Sami, 2016/02/01 11:15:07]

Now that this is WebView-specific, I guess it gives another reason for us to get
rid of the default task queues. Any idea how many systems are still using those?

[alex clarke (OOO till 29th), 2016/02/01 14:16:54]

Quite a few :(  One problem is the order in which classes are constructed in
blink.  The frame is quite late IIRC.

+  void setAllowVirtualTimeToAdvance(
+      bool allow_virtual_time_to_advance) override;
 
   // Virtual for testing.
   virtual void AddConsoleWarning(const std::string& message);
 
   scoped_ptr<WebFrameSchedulerImpl> createWebFrameSchedulerImpl();
 
  private:
   friend class WebFrameSchedulerImpl;
 
   void Unregister(WebFrameSchedulerImpl* frame_scheduler);
 
   std::set<WebFrameSchedulerImpl*> frame_schedulers_;
+  scoped_ptr<AutoAdvancingVirtualTimeDomain> virtual_time_domain_;
   blink::WebView* web_view_;
   RendererSchedulerImpl* renderer_scheduler_;
   bool page_visible_;
   bool disable_background_timer_throttling_;
+  bool allow_virtual_time_to_advance_;
 
   DISALLOW_COPY_AND_ASSIGN(WebViewSchedulerImpl);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_RENDERER_WEB_VIEW_SCHEDULER_IMPL_H_