memory_coordinator: Discard tabs under critical memory condition

content/browser/memory/memory_condition_observer.h

 // Copyright 2016 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 CONTENT_BROWSER_MEMORY_MEMORY_CONDITION_OBSERVER_H_
 #define CONTENT_BROWSER_MEMORY_MEMORY_CONDITION_OBSERVER_H_
 
 #include "base/cancelable_callback.h"
 #include "base/single_thread_task_runner.h"
 #include "base/time/time.h"
@@ skipping 19 matching lines @@
   ~MemoryConditionObserver();
 
   // Schedules a task to update memory condition. The task will be executed
   // after |delay| has passed.
   void ScheduleUpdateCondition(base::TimeDelta delay);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, CalculateNextCondition);
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, UpdateCondition);
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, ForceSetMemoryCondition);
+  FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, DiscardTabUnderCritical);
 
   // Calculates next memory condition from the amount of free memory using
   // a heuristic.
   MemoryCondition CalculateNextCondition();
 
   // Periodically called to update the memory condition.
   void UpdateCondition();
 
   MemoryCoordinatorImpl* coordinator_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
@@ skipping 28 matching lines @@
   int new_renderers_back_to_warning_;
   // The interval of checking the amount of free memory.
   base::TimeDelta monitoring_interval_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryConditionObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEMORY_MEMORY_CONDITION_OBSERVER_H_