Expands the chrome.experimental.processes extension API....

chrome/browser/extensions/extension_message_service.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/browser/extensions/extension_message_service.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/json/json_writer.h"
 #include "base/stl_util-inl.h"
 #include "base/values.h"
 #include "chrome/browser/child_process_security_policy.h"
 #include "chrome/browser/extensions/extension_process_manager.h"
+#include "chrome/browser/extensions/extension_processes_api.h"
+#include "chrome/browser/extensions/extension_processes_api_constants.h"
 #include "chrome/browser/extensions/extension_tabs_module.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/renderer_host/resource_message_filter.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/render_messages.h"
@@ skipping 144 matching lines @@
   if (!rph || rph->ListenersIterator().IsAtEnd())
     return;
 
   DCHECK_EQ(listeners_[event_name].count(render_process_id), 0u) << event_name;
   listeners_[event_name].insert(render_process_id);
 
   if (extension_devtools_manager_.get()) {
     extension_devtools_manager_->AddEventListener(event_name,
                                                   render_process_id);
   }
+
+  // We lazily tell the TaskManager to start updating when listeners to the
+  // processes.onUpdated event arrive.
+  if (event_name.compare(extension_processes_api_constants::kOnUpdated) == 0) {
+    ExtensionProcessesEventRouter::GetInstance()->ListenerAdded();
+  }
 }
 
 void ExtensionMessageService::RemoveEventListener(const std::string& event_name,
                                                   int render_process_id) {
+  // If a processes.onUpdated event listener is removed (or a process with one
+  // exits), then we let the TaskManager know that it has one fewer listener.
+  if (event_name.compare(extension_processes_api_constants::kOnUpdated) == 0) {
+    ExtensionProcessesEventRouter::GetInstance()->ListenerRemoved();
+  }
+
   // The RenderProcessHost may be destroyed. See AddEventListener.
   RenderProcessHost* rph = RenderProcessHost::FromID(render_process_id);
   if (!rph || rph->ListenersIterator().IsAtEnd())
     return;
 
   DCHECK_EQ(listeners_[event_name].count(render_process_id), 1u)
       << " PID=" << render_process_id << " event=" << event_name;
   listeners_[event_name].erase(render_process_id);
 
   if (extension_devtools_manager_.get()) {
@@ skipping 281 matching lines @@
 
     if (current->second->opener.sender == sender) {
       CloseChannelImpl(current, GET_CHANNEL_OPENER_ID(current->first),
                        notify_other_port);
     } else if (current->second->receiver.sender == sender) {
       CloseChannelImpl(current, GET_CHANNEL_RECEIVERS_ID(current->first),
                        notify_other_port);
     }
   }
 }