Keep NaCl plugins used in app background pages alive when active.

ppapi/proxy/plugin_globals.h

Index: ppapi/proxy/plugin_globals.h
diff --git a/ppapi/proxy/plugin_globals.h b/ppapi/proxy/plugin_globals.h
index bc55245d611a10c5dc154529a1749b595ef86134..918839cda12ffef44e5749767bbbe88b3a3aee0f 100644
--- a/ppapi/proxy/plugin_globals.h
+++ b/ppapi/proxy/plugin_globals.h
@@ -73,6 +73,7 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
                                       const std::string& value) OVERRIDE;
   virtual MessageLoopShared* GetCurrentMessageLoop() OVERRIDE;
   base::TaskRunner* GetFileTaskRunner() OVERRIDE;
+  virtual void MarkPluginIsActive() OVERRIDE;
 
   // Returns the channel for sending to the browser.
   IPC::Sender* GetBrowserSender();
@@ -128,12 +129,21 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
   // The embedder should call this function when the command line is known.
   void set_command_line(const std::string& c) { command_line_ = c; }
 
+  // Interval to limit how many IPC messages are sent indicating that the plugin
+  // is active and should be kept alive. The value must be smaller than any
+  // threshold used to kill inactive plugins by the embedder host.
+  int keep_aliave_throttle_interval_milliseconds();

[yzshen1, 2013/12/13 21:23:15]

alive, please. And it seems you use keepalive without '_' in the middle
elsewhere, I think it is better to be consistent.

[yzshen1, 2013/12/13 21:23:15]

const for the method, please.

[scheib, 2013/12/14 00:07:41]

Done.

[scheib, 2013/12/14 00:07:41]

Done.

+  void set_keep_aliave_throttle_interval_milliseconds(int i);
+
  private:
   class BrowserSender;
 
   // PpapiGlobals overrides.
   virtual bool IsPluginGlobals() const OVERRIDE;
 
+  // Releases the throttle on sending keepalive IPC messages.
+  void OnReleaseKeepaliveThrottle();

[yzshen1, 2013/12/13 21:23:15]

It seems better to comment that "Locks the proxy lock and releases ..."

[scheib, 2013/12/14 00:07:41]

Done.

+
   static PluginGlobals* plugin_globals_;
 
   PluginProxyDelegate* plugin_proxy_delegate_;
@@ -160,6 +170,17 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
   // lazily, since it might not be needed.
   scoped_ptr<base::Thread> file_thread_;
 
+  // Indicates activity by the plugin. Used to monitor when a plugin can be
+  // shutdown due to idleness. Current needs do not require differentiating
+  // between idle state between multiple instances, if any are active they are
+  // all considered active.
+  bool plugin_recently_active_;
+
+  int keep_aliave_throttle_interval_milliseconds_;

[yzshen1, 2013/12/13 21:23:15]

alive, please.
(You are using auto-completion for sure! :))

[scheib, 2013/12/14 00:07:41]

Done.

+
+  // Member variables should appear before the WeakPtrFactory, see weak_ptr.h.
+  base::WeakPtrFactory<PluginGlobals> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(PluginGlobals);
 };