memory coordinator: Throttle foreground renderers on SUSPENDED state

content/browser/memory/memory_coordinator.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_H_
 #define CONTENT_BROWSER_MEMORY_MEMORY_COORDINATOR_H_
 
 #include "base/memory/memory_coordinator_client_registry.h"
 #include "base/memory/memory_pressure_monitor.h"
 #include "base/process/process_handle.h"
@@ skipping 62 matching lines @@
   MemoryCoordinator();
 
   // Adds the given ChildMemoryCoordinator as a child of this coordinator.
   void AddChildForTesting(int dummy_render_process_id,
                           mojom::ChildMemoryCoordinatorPtr child);
 
   // Callback invoked by mojo when the child connection goes down. Exposed
   // for testing.
   void OnConnectionError(int render_process_id);
 
-  // Returns true when a given renderer can be throttled.
-  bool CanThrottleRenderer(int render_process_id);
-
   // Returns true when a given renderer can be suspended.
   bool CanSuspendRenderer(int render_process_id);
 
   // Stores information about any known child processes.
   struct ChildInfo {
     // This object must be compatible with STL containers.
     ChildInfo();
     ChildInfo(const ChildInfo& rhs);
     ~ChildInfo();
 
     mojom::MemoryState memory_state;
+    bool is_visible = false;
     std::unique_ptr<MemoryCoordinatorHandleImpl> handle;
   };
 
   // A map from process ID (RenderProcessHost::GetID()) to child process info.
   using ChildInfoMap = std::map<int, ChildInfo>;
 
   ChildInfoMap& children() { return children_; }
 
 private:
 #if !defined(OS_MACOSX)
@@ skipping 18 matching lines @@
   ChildInfoMap children_;
 
   std::unique_ptr<MemoryCoordinatorDelegate> delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryCoordinator);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEMORY_MEMORY_COORDINATOR_H_