Plugin Power Saver: Implement size-based heuristic for peripheral content.

content/renderer/pepper/plugin_power_saver_helper.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_PLUGIN_POWER_SAVER_HELPER_H_
+#define CONTENT_RENDERER_PEPPER_PLUGIN_POWER_SAVER_HELPER_H_
+
+#include <set>
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "content/public/renderer/render_frame_observer.h"
+#include "url/gurl.h"
+
+namespace content {
+
+// PluginPowerSaverWhitelist manages the plugin content origin whitelist for
+// a single render frame.
+class CONTENT_EXPORT PluginPowerSaverHelper : public RenderFrameObserver {
+ public:
+  explicit PluginPowerSaverHelper(RenderFrame* render_frame);
+  virtual ~PluginPowerSaverHelper();
+
+  // Returns true if this plugin should have power saver enabled.
+  //
+  // Power Saver is enabled for plugin content that are cross-origin and
+  // heuristically determined to be not the "main attraction" of the webpage.
+  //
+  // Plugin content is defined to be cross-origin when the plugin source's
+  // origin differs from the top level frame's origin. For example:
+  //  - Cross-origin:  a.com -> b.com/plugin.swf
+  //  - Cross-origin:  a.com -> b.com/iframe.html -> b.com/plugin.swf
+  //  - Same-origin:   a.com -> b.com/iframe-to-a.html -> a.com/plugin.swf
+  //
+  // |cross_origin| may not be NULL.
+  bool ShouldThrottleContent(const GURL& content_origin,
+                             int width,
+                             int height,
+                             bool* cross_origin) const;
+
+  // Registers a plugin that has been marked peripheral. If the origin
+  // whitelist is later updated and includes |content_origin|, then
+  // |unthrottle_callback| will be called.
+  void RegisterPeripheralPlugin(const GURL& content_origin,
+                                const base::Closure& unthrottle_callback);
+
+  void WhitelistContentOrigin(const GURL& content_origin);
+
+ private:
+  struct PeripheralPlugin {
+    PeripheralPlugin(const GURL& content_origin,
+                     const base::Closure& unthrottle_callback);
+    ~PeripheralPlugin();
+
+    GURL content_origin;
+    base::Closure unthrottle_callback;
+  };
+
+  // RenderFrameObserver implementation.
+  void DidCommitProvisionalLoad(bool is_new_navigation) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
+
+  void OnUpdatePluginContentOriginWhitelist(
+      const std::set<GURL>& origin_whitelist);
+
+  // Local copy of the whitelist for the entire tab.
+  std::set<GURL> origin_whitelist_;
+
+  // Set of peripheral plugins eligible to be unthrottled ex post facto.
+  std::vector<PeripheralPlugin> peripheral_plugins_;
+
+  DISALLOW_COPY_AND_ASSIGN(PluginPowerSaverHelper);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_PEPPER_PLUGIN_POWER_SAVER_HELPER_H_