Exposes a chrome.devtools object to extensions. This allows extensions to call chrome.devtools.connect() to open up a Port by which it can receive devtools messages to implement the proposed perf trace extensions API documented here:

http://code.google.com/p/chromium/wiki/ExtensionsPerfTraceAPI

Review URL: http://codereview.chromium.org/159882

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@24158 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 626 insertions, 5 deletions

diff --git a/chrome/browser/extensions/extension_devtools_bridge.cc b/chrome/browser/extensions/extension_devtools_bridge.cc
new file mode 100644
index 0000000..2ac456f
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_bridge.cc
@@ -0,0 +1,104 @@
+// Copyright (c) 2009 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_devtools_bridge.h"
+
+#include "base/message_loop.h"
+#include "base/string_util.h"
+#include "chrome/browser/debugger/devtools_manager.h"
+#include "chrome/browser/extensions/extension_devtools_events.h"
+#include "chrome/browser/extensions/extension_devtools_manager.h"
+#include "chrome/browser/extensions/extension_tabs_module.h"
+#include "chrome/browser/profile.h"
+#include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/common/devtools_messages.h"
+
+ExtensionDevToolsBridge::ExtensionDevToolsBridge(int tab_id,
+                                                 Profile* profile)
+    : tab_id_(tab_id),
+      inspected_rvh_(NULL),
+      profile_(profile),
+      on_page_event_name_(
+          ExtensionDevToolsEvents::OnPageEventNameForTab(tab_id)),
+      on_tab_url_change_event_name_(
+          ExtensionDevToolsEvents::OnTabUrlChangeEventNameForTab(tab_id)),
+      on_tab_close_event_name_(
+          ExtensionDevToolsEvents::OnTabCloseEventNameForTab(tab_id)) {
+  extension_devtools_manager_ = profile_->GetExtensionDevToolsManager();
+  DCHECK(extension_devtools_manager_.get());
+}
+
+ExtensionDevToolsBridge::~ExtensionDevToolsBridge() {
+}
+
+bool ExtensionDevToolsBridge::RegisterAsDevToolsClientHost() {
+  DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
+
+  Browser* browser;
+  TabStripModel* tab_strip;
+  TabContents* contents;
+  int tab_index;
+  if (ExtensionTabUtil::GetTabById(tab_id_, profile_, &browser, &tab_strip,
+                                   &contents, &tab_index)) {
+    inspected_rvh_ = contents->render_view_host();
+    DevToolsManager::GetInstance()->RegisterDevToolsClientHostFor(
+        inspected_rvh_, this);
+    return true;
+  }
+  return false;
+}
+
+void ExtensionDevToolsBridge::UnregisterAsDevToolsClientHost() {
+  DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
+
+  if (inspected_rvh_) {
+    DevToolsManager::GetInstance()->UnregisterDevToolsClientHostFor(
+        inspected_rvh_);
+    inspected_rvh_ = NULL;
+  }
+}
+
+// If the tab we are looking at is going away then we fire a closing event at
+// the extension.
+void ExtensionDevToolsBridge::InspectedTabClosing() {
+  DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
+
+  std::string json("[{}]");
+  profile_->GetExtensionMessageService()->
+      DispatchEventToRenderers(on_tab_close_event_name_, json);
+
+  // This may result in this object being destroyed.
+  extension_devtools_manager_->BridgeClosingForTab(tab_id_);
+}
+
+void ExtensionDevToolsBridge::SendMessageToClient(const IPC::Message& msg) {
+  IPC_BEGIN_MESSAGE_MAP(ExtensionDevToolsBridge, msg)
+    IPC_MESSAGE_HANDLER(DevToolsClientMsg_RpcMessage, OnRpcMessage);
+    IPC_MESSAGE_UNHANDLED_ERROR()
+  IPC_END_MESSAGE_MAP()
+}
+
+static const char kTimelineAgentClassName[] = "TimelineAgentClass";
+static const char kPageEventMessageName[] = "PageEventMessage";
+static const char kTabUrlChangeEventMessageName[] = "TabUrlChangeEventMessage";
+
+void ExtensionDevToolsBridge::OnRpcMessage(const std::string& class_name,
+                                           const std::string& message_name,
+                                           const std::string& msg) {
+  DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
+  // TODO(jamesr): Update the filtering and message creation logic once
+  // the TimelineAgent lands in WebKit.
+  if (class_name == kTimelineAgentClassName) {
+    if (message_name == kPageEventMessageName) {
+      std::string json = StringPrintf("[{\"record\": \"%s\"}]", msg.c_str());
+      profile_->GetExtensionMessageService()->
+          DispatchEventToRenderers(on_page_event_name_, json);
+    } else if (message_name == kTabUrlChangeEventMessageName) {
+      std::string json = StringPrintf("[{\"record\": \"%s\"}]", msg.c_str());
+      profile_->GetExtensionMessageService()->
+          DispatchEventToRenderers(on_tab_url_change_event_name_, json);
+    }
+  }
+}
+
diff --git a/chrome/browser/extensions/extension_devtools_bridge.h b/chrome/browser/extensions/extension_devtools_bridge.h
new file mode 100644
index 0000000..b4cb98d
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_bridge.h
@@ -0,0 +1,60 @@
+// Copyright (c) 2009 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_BRIDGE_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_BRIDGE_H_
+
+#include <string>
+
+#include "base/ref_counted.h"
+#include "chrome/browser/debugger/devtools_client_host.h"
+#include "chrome/browser/extensions/extension_devtools_manager.h"
+#include "chrome/browser/extensions/extension_message_service.h"
+
+class Profile;
+class RenderViewHost;
+
+// This class is a DevToolsClientHost that fires extension events.
+class ExtensionDevToolsBridge : public DevToolsClientHost {
+ public:
+  ExtensionDevToolsBridge(int tab_id, Profile* profile);
+  virtual ~ExtensionDevToolsBridge();
+
+  bool RegisterAsDevToolsClientHost();
+  void UnregisterAsDevToolsClientHost();
+
+  // DevToolsClientHost, called when the tab inspected by this client is
+  // closing.
+  virtual void InspectedTabClosing();
+
+  // DevToolsClientHost, called to send a message to this host.
+  virtual void SendMessageToClient(const IPC::Message& msg);
+
+ private:
+  void OnRpcMessage(const std::string& class_name,
+                    const std::string& message_name,
+                    const std::string& msg);
+
+  // ID of the tab we are monitoring.
+  int tab_id_;
+  // Host of the tab we are monitoring, NULL if not monitoring anything.
+  RenderViewHost* inspected_rvh_;
+
+  scoped_refptr<ExtensionDevToolsManager> extension_devtools_manager_;
+  scoped_refptr<ExtensionMessageService> extension_message_service_;
+
+  // Profile that owns our tab
+  Profile* profile_;
+
+  // The names of the events fired at extensions depend on the tab id,
+  // so we store the various event names in each bridge.
+  const std::string on_page_event_name_;
+  const std::string on_tab_url_change_event_name_;
+  const std::string on_tab_close_event_name_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionDevToolsBridge);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_BRIDGE_H_
+
diff --git a/chrome/browser/extensions/extension_devtools_browsertest.cc b/chrome/browser/extensions/extension_devtools_browsertest.cc
new file mode 100644
index 0000000..85d34ac
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_browsertest.cc
@@ -0,0 +1,15 @@
+// Copyright (c) 2009 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_devtools_browsertest.h"
+
+#include "chrome/common/chrome_switches.h"
+
+void ExtensionDevToolsBrowserTest::SetUpCommandLine(CommandLine* command_line) {
+  ExtensionBrowserTest::SetUpCommandLine(command_line);
+
+  command_line->AppendSwitch(switches::kEnableExtensionTimelineApi);
+}
+
+
diff --git a/chrome/browser/extensions/extension_devtools_browsertest.h b/chrome/browser/extensions/extension_devtools_browsertest.h
new file mode 100644
index 0000000..7fa6435
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_browsertest.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2009 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_BROWSERTEST_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_BROWSERTEST_H_
+
+#include "base/command_line.h"
+#include "chrome/browser/extensions/extension_browsertest.h"
+
+// Subclass of ExtensionBrowserTest that enables the devtools
+// command line features.
+class ExtensionDevToolsBrowserTest : public ExtensionBrowserTest {
+ protected:
+  virtual void SetUpCommandLine(CommandLine* command_line);
+
+ private:
+
+  NotificationRegistrar registrar_;
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_BROWSERTEST_H_
diff --git a/chrome/browser/extensions/extension_devtools_browsertests.cc b/chrome/browser/extensions/extension_devtools_browsertests.cc
new file mode 100644
index 0000000..9aaa071
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_browsertests.cc
@@ -0,0 +1,170 @@
+// Copyright (c) 2009 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 "base/ref_counted.h"
+#include "chrome/browser/browser.h"
+#include "chrome/browser/browser_list.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/browser/debugger/devtools_manager.h"
+#include "chrome/browser/debugger/devtools_client_host.h"
+#include "chrome/browser/extensions/extension_devtools_browsertest.h"
+#include "chrome/browser/extensions/extension_host.h"
+#include "chrome/browser/extensions/extension_process_manager.h"
+#include "chrome/browser/extensions/extensions_service.h"
+#include "chrome/browser/extensions/extension_tabs_module.h"
+#include "chrome/browser/profile.h"
+#include "chrome/browser/renderer_host/site_instance.h"
+#include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/browser/views/extensions/extension_shelf.h"
+#include "chrome/browser/views/frame/browser_view.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/common/devtools_messages.h"
+#include "chrome/common/extensions/extension_error_reporter.h"
+#include "chrome/common/notification_service.h"
+#include "chrome/common/url_constants.h"
+#include "chrome/test/ui_test_utils.h"
+#include "net/base/net_util.h"
+
+// Looks for an ExtensionHost whose URL has the given path component (including
+// leading slash).  Also verifies that the expected number of hosts are loaded.
+static ExtensionHost* FindHostWithPath(ExtensionProcessManager* manager,
+                                       const std::string& path,
+                                       int expected_hosts) {
+  ExtensionHost* host = NULL;
+  int num_hosts = 0;
+  for (ExtensionProcessManager::const_iterator iter = manager->begin();
+       iter != manager->end(); ++iter) {
+    if ((*iter)->GetURL().path() == path) {
+      EXPECT_FALSE(host);
+      host = *iter;
+    }
+    num_hosts++;
+  }
+  EXPECT_EQ(expected_hosts, num_hosts);
+  EXPECT_TRUE(host);
+  return host;
+}
+
+// Tests for the experimental timeline extensions API.
+IN_PROC_BROWSER_TEST_F(ExtensionDevToolsBrowserTest, TimelineApi) {
+  ASSERT_TRUE(LoadExtension(
+      test_data_dir_.AppendASCII("devtools").AppendASCII("timeline_api")));
+
+  // Get the ExtensionHost that is hosting our background page.
+  ExtensionProcessManager* manager =
+      browser()->profile()->GetExtensionProcessManager();
+  ExtensionHost* host = FindHostWithPath(manager, "/background.html", 1);
+
+  // Grab a handle to the DevToolsManager so we can forward messages to it.
+  DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
+
+  // Grab the tab_id of whatever tab happens to be first.
+  TabContents* tab_contents = browser()->tabstrip_model()->GetTabContentsAt(0);
+  ASSERT_TRUE(tab_contents);
+  int tab_id = ExtensionTabUtil::GetTabId(tab_contents);
+  
+  // Test setup.
+  bool result = false;
+  std::wstring register_listeners_js = StringPrintf(L"setListenersOnTab(%d)",
+                                                    tab_id);
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host->render_view_host(), L"", register_listeners_js, &result);
+  EXPECT_TRUE(result);
+
+  // Setting the events should have caused an ExtensionDevToolsBridge to be
+  // registered for the tab's RenderViewHost.
+  DevToolsClientHost* devtools_client_host =
+      devtools_manager->GetDevToolsClientHostFor(
+          tab_contents->render_view_host());
+  ASSERT_TRUE(devtools_client_host);
+
+  // Test onTabUrlChange event.
+  DevToolsClientMsg_RpcMessage tabUrlChangeEventMessage(
+      "TimelineAgentClass", "TabUrlChangeEventMessage", "{}");
+  devtools_client_host->SendMessageToClient(tabUrlChangeEventMessage);
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host->render_view_host(),
+      L"",
+      L"testReceiveTabUrlChangeEvent()",
+      &result);
+  EXPECT_TRUE(result);
+
+  // Test onPageEvent event.
+  result = false;
+  DevToolsClientMsg_RpcMessage pageEventMessage(
+      "TimelineAgentClass", "PageEventMessage", "{}");
+  devtools_client_host->SendMessageToClient(pageEventMessage);
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host->render_view_host(), L"", L"testReceivePageEvent()", &result);
+  EXPECT_TRUE(result);
+
+  // Test onTabClose event.
+  result = false;
+  devtools_manager->UnregisterDevToolsClientHostFor(
+      tab_contents->render_view_host());
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host->render_view_host(), L"", L"testReceiveTabCloseEvent()", &result);
+  EXPECT_TRUE(result);
+}
+
+
+// Tests that ref counting of listeners from multiple processes works.
+IN_PROC_BROWSER_TEST_F(ExtensionDevToolsBrowserTest, ProcessRefCounting) {
+  ASSERT_TRUE(LoadExtension(
+      test_data_dir_.AppendASCII("devtools").AppendASCII("timeline_api")));
+
+  // Get the ExtensionHost that is hosting our background page.
+  ExtensionProcessManager* manager =
+      browser()->profile()->GetExtensionProcessManager();
+  ExtensionHost* host_one = FindHostWithPath(manager, "/background.html", 1);
+
+  ASSERT_TRUE(LoadExtension(
+      test_data_dir_.AppendASCII("devtools").AppendASCII("timeline_api_two")));
+  ExtensionHost* host_two = FindHostWithPath(manager,
+                                             "/background_two.html", 2);
+
+  DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
+
+  // Grab the tab_id of whatever tab happens to be first.
+  TabContents* tab_contents = browser()->tabstrip_model()->GetTabContentsAt(0);
+  ASSERT_TRUE(tab_contents);
+  int tab_id = ExtensionTabUtil::GetTabId(tab_contents);
+  
+  // Test setup.
+  bool result = false;
+  std::wstring register_listeners_js = StringPrintf(L"setListenersOnTab(%d)",
+                                                    tab_id);
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host_one->render_view_host(), L"", register_listeners_js, &result);
+  EXPECT_TRUE(result);
+
+  // Setting the event listeners should have caused an ExtensionDevToolsBridge
+  // to be registered for the tab's RenderViewHost.
+  ASSERT_TRUE(devtools_manager->GetDevToolsClientHostFor(
+      tab_contents->render_view_host()));
+
+  // Register listeners from the second extension as well.
+  std::wstring script = StringPrintf(L"registerListenersForTab(%d)", tab_id);
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host_two->render_view_host(), L"", script, &result);
+  EXPECT_TRUE(result);
+
+  // Removing the listeners from the first extension should leave the bridge
+  // alive.
+  result = false;
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host_one->render_view_host(), L"", L"unregisterListeners()", &result);
+  EXPECT_TRUE(result);
+  ASSERT_TRUE(devtools_manager->GetDevToolsClientHostFor(
+      tab_contents->render_view_host()));
+
+  // Removing the listeners from the second extension should tear the bridge
+  // down.
+  result = false;
+  ui_test_utils::ExecuteJavaScriptAndExtractBool(
+      host_two->render_view_host(), L"", L"unregisterListeners()", &result);
+  EXPECT_TRUE(result);
+  ASSERT_FALSE(devtools_manager->GetDevToolsClientHostFor(
+      tab_contents->render_view_host()));
+}
diff --git a/chrome/browser/extensions/extension_devtools_events.cc b/chrome/browser/extensions/extension_devtools_events.cc
new file mode 100644
index 0000000..979726c
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_events.cc
@@ -0,0 +1,60 @@
+// Copyright (c) 2009 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_devtools_events.h"
+
+#include <vector>
+
+#include "base/string_util.h"
+
+// These string constants and the formats used in this file must stay
+// in sync with chrome/renderer/resources/extension_process_bindings.js
+static const char kDevToolsEventPrefix[] = "devtools.";
+static const char kOnPageEventName[] = "onPageEvent";
+static const char kOnTabUrlChangeEventName[] = "onTabUrlChange";
+static const char kOnTabCloseEventName[] = "onTabClose";
+
+// static
+bool ExtensionDevToolsEvents::IsDevToolsEventName(
+    const std::string& event_name, int* tab_id) {
+  // We only care about events of the form "devtools.34.*", where 34 is
+  // a tab id.
+  if (IsStringASCII(event_name) &&
+      StartsWithASCII(event_name,
+                      kDevToolsEventPrefix,
+                      true /* case_sensitive */)) {
+    // At this point we want something like "4.onPageEvent"
+    std::vector<std::string> parts;
+    SplitString(event_name.substr(strlen(kDevToolsEventPrefix)), '.', &parts);
+    if (parts.size() == 2 && StringToInt(parts[0], tab_id)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+// static
+std::string ExtensionDevToolsEvents::OnPageEventNameForTab(int tab_id) {
+  return StringPrintf("%s%d.%s",
+                      kDevToolsEventPrefix,
+                      tab_id,
+                      kOnPageEventName);
+}
+
+// static
+std::string ExtensionDevToolsEvents::OnTabUrlChangeEventNameForTab(int tab_id) {
+  return StringPrintf("%s%d.%s",
+                      kDevToolsEventPrefix,
+                      tab_id,
+                      kOnTabUrlChangeEventName);
+}
+
+// static
+std::string ExtensionDevToolsEvents::OnTabCloseEventNameForTab(int tab_id) {
+  return StringPrintf("%s%d.%s",
+                      kDevToolsEventPrefix,
+                      tab_id,
+                      kOnTabCloseEventName);
+}
+
diff --git a/chrome/browser/extensions/extension_devtools_events.h b/chrome/browser/extensions/extension_devtools_events.h
new file mode 100644
index 0000000..ff985b2
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_events.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2009 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_EVENTS_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_EVENTS_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+
+// Static utility functions for dealing with extension devtools event names.
+// The format of the event names is <prefix>.<tab id>.<event name>
+// Equivalent name munging is done in the extension process in JavaScript
+// by chrome/renderer/resources/extension_process_bindings.js
+class ExtensionDevToolsEvents {
+ public:
+  // Checks if an event name is a magic devtools event name.  If so,
+  // the tab id of the event is put in *tab_id.
+  static bool IsDevToolsEventName(const std::string& event_name, int* tab_id);
+
+  // Generates the event string for an onPageEvent for a given tab.
+  static std::string OnPageEventNameForTab(int tab_id);
+
+  // Generates the event string for an onPageEvent for a given tab.
+  static std::string OnTabUrlChangeEventNameForTab(int tab_id);
+
+  // Generates the event string for an onTabCloseEvent for a given tab.
+  static std::string OnTabCloseEventNameForTab(int tab_id);
+
+ private:
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ExtensionDevToolsEvents);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_EVENTS_H_
+
diff --git a/chrome/browser/extensions/extension_devtools_manager.cc b/chrome/browser/extensions/extension_devtools_manager.cc
new file mode 100644
index 0000000..20f4eb0
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_manager.cc
@@ -0,0 +1,72 @@
+// Copyright (c) 2009 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_devtools_manager.h"
+
+#include "base/message_loop.h"
+#include "base/string_util.h"
+#include "base/task.h"
+#include "chrome/browser/extensions/extension_devtools_bridge.h"
+#include "chrome/browser/extensions/extension_devtools_events.h"
+
+ExtensionDevToolsManager::ExtensionDevToolsManager(Profile* profile)
+    : profile_(profile),
+      ui_loop_(NULL) {
+  DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
+  ui_loop_ = MessageLoop::current();
+}
+
+ExtensionDevToolsManager::~ExtensionDevToolsManager() {
+}
+
+void ExtensionDevToolsManager::AddEventListener(const std::string& event_name,
+                                                int render_process_id) {
+  int tab_id;
+  if (ExtensionDevToolsEvents::IsDevToolsEventName(event_name, &tab_id)) {
+    // Add the renderer process ID to the set of processes interested
+    // in this tab.
+    tab_id_to_render_process_ids_[tab_id].insert(render_process_id);
+    if (tab_id_to_bridge_.count(tab_id) == 0) {
+      // Create a new bridge for this tab if there isn't one already.
+      linked_ptr<ExtensionDevToolsBridge> bridge(
+          new ExtensionDevToolsBridge(tab_id, profile_));
+      if (bridge->RegisterAsDevToolsClientHost()) {
+        tab_id_to_bridge_[tab_id] = bridge;
+      }
+    }
+  }
+}
+
+void ExtensionDevToolsManager::RemoveEventListener(
+    const std::string& event_name,
+    int render_process_id) {
+  int tab_id;
+  if (ExtensionDevToolsEvents::IsDevToolsEventName(event_name, &tab_id)) {
+    std::map<int, std::set<int> >::iterator it =
+        tab_id_to_render_process_ids_.find(tab_id);
+    if (it != tab_id_to_render_process_ids_.end()) {
+      // Remove the process from the set of processes interested in this tab.
+      it->second.erase(render_process_id);
+      if (it->second.empty()) {
+        // No renderers have registered listeners for this tab, so kill the
+        // bridge if there is one.
+        if (tab_id_to_bridge_.count(tab_id) != 0) {
+          linked_ptr<ExtensionDevToolsBridge> bridge(tab_id_to_bridge_[tab_id]);
+          bridge->UnregisterAsDevToolsClientHost();
+          tab_id_to_bridge_.erase(tab_id);
+        }
+      }
+    }
+  }
+}
+
+void ExtensionDevToolsManager::BridgeClosingForTab(int tab_id) {
+  if (tab_id_to_bridge_.count(tab_id) != 0) {
+    linked_ptr<ExtensionDevToolsBridge> bridge(tab_id_to_bridge_[tab_id]);
+    bridge->UnregisterAsDevToolsClientHost();
+    tab_id_to_bridge_.erase(tab_id);
+  }
+  tab_id_to_render_process_ids_.erase(tab_id);
+}
+
diff --git a/chrome/browser/extensions/extension_devtools_manager.h b/chrome/browser/extensions/extension_devtools_manager.h
new file mode 100644
index 0000000..35e7cec
--- /dev/null
+++ b/chrome/browser/extensions/extension_devtools_manager.h
@@ -0,0 +1,63 @@
+// Copyright (c) 2009 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_MANAGER_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_MANAGER_H_
+
+#include <map>
+#include <set>
+#include <string>
+#include "base/linked_ptr.h"
+#include "base/ref_counted.h"
+
+class ExtensionDevToolsBridge;
+class MessageLoop;
+class Profile;
+
+// This class manages the lifetimes of ExtensionDevToolsBridge objects.
+// The manager is owned by the Profile.
+//
+// The lifetime of an ExtensionDevToolsBridge object is determined by:
+//  * the existence of registered event handlers for the bridge's tab
+//  * the lifetime of the inspected tab
+//
+// The manager is alerted whenever an event listener is added or removed and
+// keeps track of the set of renderers with event listeners registered for each
+// tab.  A new bridge object is created for a tab when the first event listener
+// is registered on that tab.  A bridge object is destroyed when all event
+// listeners are removed, the inspected tab closes, or when the manager itself
+// is destroyed.
+
+class ExtensionDevToolsManager
+    : public base::RefCountedThreadSafe<ExtensionDevToolsManager> {
+ public:
+  // UI thread only:
+  explicit ExtensionDevToolsManager(Profile* profile);
+  ~ExtensionDevToolsManager();
+
+  void AddEventListener(const std::string& event_name,
+                        int render_process_id);
+
+  void RemoveEventListener(const std::string& event_name,
+                           int render_process_id);
+
+  void BridgeClosingForTab(int tab_id);
+
+ private:
+
+  // Map of tab IDs to the ExtensionDevToolsBridge connected to the tab
+  std::map<int, linked_ptr<ExtensionDevToolsBridge> > tab_id_to_bridge_;
+
+  // Map of tab IDs to the set of render_process_ids that have registered
+  // event handlers for the tab.
+  std::map<int, std::set<int> > tab_id_to_render_process_ids_;
+
+  Profile* profile_;
+  MessageLoop* ui_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionDevToolsManager);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_DEVTOOLS_MANAGER_H_
+
diff --git a/chrome/browser/extensions/extension_message_service.cc b/chrome/browser/extensions/extension_message_service.cc
index a4b1fd6d..edc2cf9 100644
--- a/chrome/browser/extensions/extension_message_service.cc
+++ b/chrome/browser/extensions/extension_message_service.cc
@@ -105,7 +105,10 @@ const char ExtensionMessageService::kDispatchEvent[] =
     "Event.dispatchJSON";
 
 ExtensionMessageService::ExtensionMessageService(Profile* profile)
-    : ui_loop_(MessageLoop::current()), profile_(profile), next_port_id_(0) {
+    : ui_loop_(MessageLoop::current()),
+      profile_(profile),
+      extension_devtools_manager_(NULL),
+      next_port_id_(0) {
   DCHECK_EQ(ui_loop_->type(), MessageLoop::TYPE_UI);
 
   registrar_.Add(this, NotificationType::RENDERER_PROCESS_TERMINATED,
@@ -114,6 +117,8 @@ ExtensionMessageService::ExtensionMessageService(Profile* profile)
                  NotificationService::AllSources());
   registrar_.Add(this, NotificationType::RENDER_VIEW_HOST_DELETED,
                  NotificationService::AllSources());
+
+  extension_devtools_manager_ = profile_->GetExtensionDevToolsManager();
 }
 
 ExtensionMessageService::~ExtensionMessageService() {
@@ -136,6 +141,11 @@ void ExtensionMessageService::AddEventListener(const std::string& event_name,
   DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
   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);
+  }
 }
 
 void ExtensionMessageService::RemoveEventListener(const std::string& event_name,
@@ -149,6 +159,11 @@ void ExtensionMessageService::RemoveEventListener(const std::string& event_name,
   DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
   DCHECK_EQ(listeners_[event_name].count(render_process_id), 1u) << event_name;
   listeners_[event_name].erase(render_process_id);
+
+  if (extension_devtools_manager_.get()) {
+    extension_devtools_manager_->RemoveEventListener(event_name,
+                                                     render_process_id);
+  }
 }
 
 void ExtensionMessageService::AllocatePortIdPair(int* port1, int* port2) {
@@ -345,6 +360,7 @@ void ExtensionMessageService::CloseChannelImpl(
   channels_.erase(channel_iter);
 }
 
+
 void ExtensionMessageService::PostMessageFromRenderer(
     int source_port_id, const std::string& message) {
   DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
@@ -394,13 +410,12 @@ void ExtensionMessageService::Observe(NotificationType type,
       RenderProcessHost* renderer = Source<RenderProcessHost>(source).ptr();
       OnSenderClosed(renderer);
 
-      // Remove this renderer from our listener maps.
+      // Remove all event listeners associated with this renderer
       for (ListenerMap::iterator it = listeners_.begin();
            it != listeners_.end(); ) {
         ListenerMap::iterator current = it++;
-        current->second.erase(renderer->pid());
-        if (current->second.empty())
-          listeners_.erase(current);
+        if (current->second.count(renderer->pid()) != 0)
+          RemoveEventListener(current->first, renderer->pid());
       }
       break;
     }
diff --git a/chrome/browser/extensions/extension_message_service.h b/chrome/browser/extensions/extension_message_service.h
index a6b1cd5..32ed945 100644
--- a/chrome/browser/extensions/extension_message_service.h
+++ b/chrome/browser/extensions/extension_message_service.h
@@ -13,6 +13,7 @@
 #include "base/lock.h"
 #include "base/ref_counted.h"
 #include "chrome/common/notification_registrar.h"
+#include "chrome/browser/extensions/extension_devtools_manager.h"
 #include "ipc/ipc_message.h"
 
 class MessageLoop;
@@ -157,6 +158,8 @@ class ExtensionMessageService
 
   MessageChannelMap channels_;
 
+  scoped_refptr<ExtensionDevToolsManager> extension_devtools_manager_;
+
   // A map between an event name and a set of process id's that are listening
   // to that event.
   typedef std::map<std::string, std::set<int> > ListenerMap;