Test Keeping NaCl plugins used in app background pages alive when active.

extensions/browser/process_manager.h

Index: extensions/browser/process_manager.h
diff --git a/extensions/browser/process_manager.h b/extensions/browser/process_manager.h
index 379c3648d527cd2e14e199abe4c12de960dea0ff..c9029490339fca3d4315d47fae8ed9c2c93c3bfe 100644
--- a/extensions/browser/process_manager.h
+++ b/extensions/browser/process_manager.h
@@ -125,6 +125,14 @@ class ProcessManager : public content::NotificationObserver {
   // related SiteInstances.
   content::BrowserContext* GetBrowserContext() const;
 
+  // Sets callbacks for testing keepalive impulse behavior.
+  typedef base::Callback<void(const std::string& extension_id)>
+      ImpulseCallbackForTesting;
+  void SetKeepaliveImpulseCallbackForTesting(
+      const ImpulseCallbackForTesting& callback);
+  void SetKeepaliveImpulseDecrementCallbackForTesting(
+      const ImpulseCallbackForTesting& callback);
+
  protected:
   // If |context| is incognito pass the master context as |original_context|.
   // Otherwise pass the same context for both.
@@ -223,6 +231,9 @@ class ProcessManager : public content::NotificationObserver {
 
   base::Callback<void(content::DevToolsAgentHost*, bool)> devtools_callback_;
 
+  ImpulseCallbackForTesting keepalive_impulse_callback_for_testing_;
+  ImpulseCallbackForTesting keepalive_impulse_decrement_callback_for_testing_;
+
   base::WeakPtrFactory<ProcessManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessManager);