[scheduler] Fix --disable-background-timer-throttling flag.

third_party/WebKit/Source/platform/scheduler/child/web_scheduler.h

 // 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.
 
 #ifndef THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_WEB_SCHEDULER_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_WEB_SCHEDULER_H_
 
 #include "platform/scheduler/renderer/web_view_scheduler.h"
 #include "public/platform/WebString.h"
 #include "public/platform/WebThread.h"
@@ skipping 77 matching lines @@
 
   // Tells the scheduler that a navigation task is pending.
   // TODO(alexclarke): Long term should this be a task trait?
   virtual void AddPendingNavigation(
       scheduler::RendererScheduler::NavigatingFrameType) = 0;
 
   // Tells the scheduler that a navigation task is no longer pending.
   virtual void RemovePendingNavigation(
       scheduler::RendererScheduler::NavigatingFrameType) = 0;
 
+  // Test helpers.
+
+  // Return a reference to an underlying RendererScheduler object.
+  // Can be null if there is no underlying RendererScheduler
+  // (e.g. worker threads).
+  virtual scheduler::RendererScheduler* GetRendererSchedulerForTest() {
+    return nullptr;
+  }
+
 #ifdef INSIDE_BLINK
   // Helpers for posting bound functions as tasks.
   typedef Function<void(double deadline_seconds)> IdleTask;
 
   void PostIdleTask(const WebTraceLocation&, std::unique_ptr<IdleTask>);
   void PostNonNestableIdleTask(const WebTraceLocation&,
                                std::unique_ptr<IdleTask>);
 #endif
 };
 
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_WEB_SCHEDULER_H_