Expose MemoryCoordinator's global budget information.

content/browser/memory/memory_coordinator_impl.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_COORDINATOR_IMPL_H_
 #define CONTENT_BROWSER_MEMORY_MEMORY_COORDINATOR_IMPL_H_
 
 #include "base/callback.h"
 #include "base/memory/singleton.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 29 matching lines @@
                                              public NotificationObserver,
                                              public base::NonThreadSafe {
  public:
   MemoryCoordinatorImpl(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
                         std::unique_ptr<MemoryMonitor> monitor);
   ~MemoryCoordinatorImpl() override;
 
   // MemoryCoordinator implementations:
   void Start() override;
   void OnChildAdded(int render_process_id) override;
+  base::MemoryState GetCurrentMemoryState() const override;
+  void SetCurrentMemoryStateForTesting(base::MemoryState memory_state) override;
+  int64_t GetRemainingGlobalBudget() const override;
 
   MemoryMonitor* memory_monitor() { return memory_monitor_.get(); }
 
-  base::MemoryState GetCurrentMemoryState() const override;
-  void SetCurrentMemoryStateForTesting(base::MemoryState memory_state) override;
-
   // NotificationObserver implementation:
   void Observe(int type,
                const NotificationSource& source,
                const NotificationDetails& details) override;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, CalculateNextState);
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, UpdateState);
   FRIEND_TEST_ALL_PREFIXES(MemoryCoordinatorImplTest, SetMemoryStateForTesting);
 
   friend struct MemoryCoordinatorSingletonTraits;
 
   using MemoryState = base::MemoryState;
 
   // Calculates the next global state from the amount of free memory using
   // a heuristic.
-  MemoryState CalculateNextState();
+  MemoryState CalculateNextState(int free_memory_until_critical_mb);

[haraken, 2016/11/05 12:52:21]

int => int64_t ?

[chrisha, 2016/11/07 19:33:41]

(Decided to move everything in the other direction.)

+
+  // Calculates the remaining global budget.
+  int64_t CalculateRemainingGlobalBudget(int free_memory_until_critical_mb);
 
   // Updates the global state and notifies state changes to clients (lives in
   // the browser) and child processes (renderers) if necessary.
   void UpdateState();
 
   // Notifies a state change to in-process clients.
   void NotifyStateToClients();
 
   // Notifies a state change to child processes.
   void NotifyStateToChildren();
 
+  // Notifies a change in remaining global budget to children.
+  void NotifyRemainingGlobalBudgetToChildren();
+
   // Schedules a task to update the global state. The task will be executed
   // after |delay| has passed.
   void ScheduleUpdateState(base::TimeDelta delay);
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   NotificationRegistrar notification_registrar_;
   std::unique_ptr<MemoryMonitor> memory_monitor_;
   base::Closure update_state_callback_;
   base::MemoryState current_state_ = MemoryState::NORMAL;
   base::TimeTicks last_state_change_;
+  int64_t remaining_global_budget_mb_;
 
   // Validates parameters defined below.
   bool ValidateParameters();
 
   // Parameters to control the heuristic.
 
   // The median size of a renderer on the current platform. This is used to
   // convert the amount of free memory to an expected number of new renderers
   // that could be started before hitting critical memory pressure.
   int expected_renderer_size_;
@@ skipping 19 matching lines @@
   base::TimeDelta monitoring_interval_;
 
   base::WeakPtrFactory<MemoryCoordinatorImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryCoordinatorImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEMORY_MEMORY_COORDINATOR_IMPL_H_