Plugin Power Saver: Make PepperPluginInstanceThrottler interface public.

content/renderer/pepper/plugin_instance_throttler_impl.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 CONTENT_RENDERER_PEPPER_PEPPER_PLUGIN_INSTANCE_THROTTLER_H_
-#define CONTENT_RENDERER_PEPPER_PEPPER_PLUGIN_INSTANCE_THROTTLER_H_
+#ifndef CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_
+#define CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_
 
-#include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
 #include "content/common/content_export.h"
-#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/plugin_instance_throttler.h"
 #include "ppapi/shared_impl/ppb_view_shared.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
 
 namespace blink {
 class WebInputEvent;
 }
 
-class GURL;
 class SkBitmap;
 
 namespace content {
 
-// Manages the Plugin Power Saver feature for a single Pepper plugin instance.
-//
-// A plugin must meet certain criteria in order to be throttled (e.g. it must
-// be a Flash plugin, it must meet certain size criteria, etc.). The process
-// for throttling a plugin is as follows:
-// 1) Attempt to find a representative keyframe to display as a placeholder for
-//    the plugin.
-// 2) a) If a representative keyframe is found, throttle the plugin at that
-//       keyframe.
-//    b) If a representative keyframe is not found, throttle the plugin after a
-//       certain period of time.
-//
-// The plugin will then be unthrottled by receiving a mouse click from the user.
-//
-// To choose a representative keyframe, we first wait for a certain number of
-// "interesting" frames to be displayed by the plugin. A frame is called
-// interesting if it meets some heuristic. After we have seen a certain number
-// of interesting frames, we throttle the plugin and use that frame as the
-// representative keyframe.
-class CONTENT_EXPORT PepperPluginInstanceThrottler {
+class CONTENT_EXPORT PluginInstanceThrottlerImpl
+    : public PluginInstanceThrottler {
  public:
-  // How the throttled power saver is unthrottled, if ever.
-  // These numeric values are used in UMA logs; do not change them.
-  enum PowerSaverUnthrottleMethod {
-    UNTHROTTLE_METHOD_NEVER = 0,
-    UNTHROTTLE_METHOD_BY_CLICK = 1,
-    UNTHROTTLE_METHOD_BY_WHITELIST = 2,
-    UNTHROTTLE_METHOD_BY_AUDIO = 3,
-    UNTHROTTLE_METHOD_NUM_ITEMS
-  };
+  PluginInstanceThrottlerImpl(RenderFrame* frame,
+                              const GURL& plugin_url,
+                              PluginPowerSaverMode power_saver_mode);
 
-  PepperPluginInstanceThrottler(
-      RenderFrame* frame,
-      const blink::WebRect& bounds,
-      bool is_flash_plugin,
-      const GURL& plugin_url,
-      RenderFrame::PluginPowerSaverMode power_saver_mode,
-      const base::Closure& throttle_change_callback);
+  ~PluginInstanceThrottlerImpl() override;
 
-  virtual ~PepperPluginInstanceThrottler();
+  // PluginInstanceThrottler implementation:
+  void AddObserver(Observer* observer) override;
+  void RemoveObserver(Observer* observer) override;
+  bool IsThrottled() const override;
+  void DisablePowerSaver(PowerSaverUnthrottleMethod method) override;
 
   bool needs_representative_keyframe() const {
     return needs_representative_keyframe_;
   }
 
-  bool power_saver_enabled() const {
-    return power_saver_enabled_;
-  }
+  bool power_saver_enabled() const { return power_saver_enabled_; }
 
   // Called when the plugin flushes it's graphics context. Supplies the
   // throttler with a candidate to use as the representative keyframe.
   void OnImageFlush(const SkBitmap* bitmap);
 
-  bool is_throttled() const { return plugin_throttled_; }
-
   // Returns true if |event| was handled and shouldn't be further processed.
   bool ConsumeInputEvent(const blink::WebInputEvent& event);
 
-  // Disables Power Saver and unthrottles the plugin if already throttled.
-  void DisablePowerSaver(PowerSaverUnthrottleMethod method);
-
  private:
-  friend class PepperPluginInstanceThrottlerTest;
+  friend class PluginInstanceThrottlerImplTest;
 
   void SetPluginThrottled(bool throttled);
 
-  // Plugin's bounds in view space.
-  blink::WebRect bounds_;
-
-  // Called when the throttle state changes.
-  base::Closure throttle_change_callback_;
-
-  bool is_flash_plugin_;
-
   // True if throttler is still waiting to find a representative keyframe.
   bool needs_representative_keyframe_;
 
   // Number of consecutive interesting frames we've encountered.
   int consecutive_interesting_frames_;
 
-  // Set to true first time plugin is clicked. Used to collect metrics.
-  bool has_been_clicked_;
-
   // Indicates whether this plugin may be throttled to reduce power consumption.
   // |power_saver_enabled_| implies |is_peripheral_content_|.

[Lei Zhang, 2015/01/15 01:18:38]

You still reference |is_peripheral_content_| here.

[tommycli, 2015/01/15 23:19:32]

Done.

   bool power_saver_enabled_;
 
-  // Indicates whether this plugin was found to be peripheral content.
+  // Indicates whether this plugin has been unthrottled.
   // This is separately tracked from |power_saver_enabled_| to collect UMAs.
-  // Always true if |power_saver_enabled_| is true.
-  bool is_peripheral_content_;
+  bool has_been_unthrottled_;

[Lei Zhang, 2015/01/15 01:18:38]

Now this variable name and |plugin_throttled_| below are more similar in name.
You may want to describe how the 3 bools here are related. There are 8 potential
combinations but I think only 3 or 4 are actually reachable.

[tommycli, 2015/01/15 23:19:32]

Done.

 
   // Indicates if the plugin is currently throttled.
   bool plugin_throttled_;
 
-  base::WeakPtrFactory<PepperPluginInstanceThrottler> weak_factory_;
+  ObserverList<Observer> observer_list_;
 
-  DISALLOW_COPY_AND_ASSIGN(PepperPluginInstanceThrottler);
+  base::WeakPtrFactory<PluginInstanceThrottlerImpl> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PluginInstanceThrottlerImpl);
 };
 }
 
-#endif  // CONTENT_RENDERER_PEPPER_PEPPER_PLUGIN_INSTANCE_THROTTLER_H_
+#endif  // CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_