Plugin Power Saver: Refactor Plugin Instance Throttling code

content/renderer/pepper/pepper_plugin_instance_throttler.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_
 
-#include "base/callback_forward.h"
+#include "base/callback.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "ppapi/shared_impl/ppb_view_shared.h"
+
+namespace blink {
+class WebInputEvent;
+}
 
 namespace content {
 
-// Throttles Pepper Plugin instances in Power Saver mode. Currently just a
-// stub implementation that engages throttling after a fixed timeout.
-// In the future, will examine plugin frames to find a suitable preview
-// image before engaging throttling.
+class PepperPluginInstanceImpl;
+
+// Manages the Plugin Power Saver feature for a single Pepper plugin instance.
 class PepperPluginInstanceThrottler {
  public:
-  // |throttle_closure| is called to engage throttling.
-  explicit PepperPluginInstanceThrottler(const base::Closure& throttle_closure);
+  PepperPluginInstanceThrottler(PepperPluginInstanceImpl* instance,
+                                const base::Closure& throttle_change_callback);
 
   virtual ~PepperPluginInstanceThrottler();
 
+  bool is_throttled() const { return plugin_throttled_; }
+  const ppapi::ViewData& throttled_view_data() const {
+    return empty_view_data_;
+  }
+
+  // Returns true if |event| was handled and shouldn't be further processed.
+  bool ConsumeInputEvent(const blink::WebInputEvent& event);
+
+ protected:
+  // Used only for testing.
+  PepperPluginInstanceThrottler(const base::Closure& throttle_change_callback,
+                                bool power_saver_enabled,
+                                bool is_peripheral_content);
+
+  void SetPluginThrottled(bool throttled);
+  void DisablePowerSaverByRetroactiveWhitelist();
+
  private:
+  // Called when the throttle state changes.
+  base::Closure throttle_change_callback_;
+
+  // Indicates whether this plugin may be throttled to reduce power consumption.
+  // |power_saver_enabled_| implies |is_peripheral_content_|.
+  bool power_saver_enabled_;
+
+  // Indicates whether this plugin was found to be peripheral content.
+  // This is separately tracked from |power_saver_enabled_| to collect UMAs.
+  // Always true if |power_saver_enabled_| is true.
+  bool is_peripheral_content_;
+
+  // Indicates if the plugin is currently throttled.
+  bool plugin_throttled_;
+
+  // Fake view data used by the Power Saver feature to throttle plugins.
+  const ppapi::ViewData empty_view_data_;
+
+  base::WeakPtrFactory<PepperPluginInstanceThrottler> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(PepperPluginInstanceThrottler);
 };
 }
 
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_PLUGIN_INSTANCE_THROTTLER_H_