Define DevTools content API

The API consists of the following parts:
* DevToolsManager routes messages between devtools agents and clients
* DevToolsAgentHost provides an abstract interface to the debuggee, currently it is either RenderViewHost or Shared Worker. Client can obtain DevToolsAgentHost from DevToolsAgentHostRegistry.
* DevToolsClientHost is an API that should be implemented by DevTools front-end. There is a default Chromium implementation living in chrome/ and a remote debugging server which also implements this interface. Clients can extend it in order to provide custom front-end. There is a default DevTools front-end implementation and content/ provides a way for creating corresponding DevToolsClientHost by means of DevToolsClientHost::CreateDevToolsFrontendHost. The embedder just needs to provide a concrete delegate.
* This patch also removes DevToolsHost_ForwardToAgent and DevToolsHost_ForwardToClient IPC messages which were used to forward only one message. DevTools IPC messages are now hidden behind the devtools content API.

BUG=104625
TEST=Existing tests

Review URL: http://codereview.chromium.org/8549022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@112473 0039d316-1c4b-4281-b951-d872f2087c98

48 files changed, 828 insertions, 644 deletions

diff --git a/chrome/browser/DEPS b/chrome/browser/DEPS
index 72cdae8..2d92a3a 100644
--- a/chrome/browser/DEPS
+++ b/chrome/browser/DEPS
@@ -36,8 +36,6 @@ include_rules = [
   "+content/common/chrome_application_mac.h",
   "+content/common/mac/scoped_sending_event.h",
   "+content/common/view_messages.h",
-  # TODO(pfeldman)
-  "+content/common/devtools_messages.h",
   # TODO(gbilock)
   "+content/common/intents_messages.h",
 
diff --git a/chrome/browser/automation/automation_provider.cc b/chrome/browser/automation/automation_provider.cc
index a48ad44..e6ee1d1 100644
--- a/chrome/browser/automation/automation_provider.cc
+++ b/chrome/browser/automation/automation_provider.cc
@@ -79,7 +79,6 @@
 #include "chrome/common/pref_names.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/download/download_item.h"
 #include "content/browser/download/save_package.h"
 #include "content/browser/renderer_host/render_view_host.h"
diff --git a/chrome/browser/debugger/devtools_sanity_unittest.cc b/chrome/browser/debugger/devtools_sanity_unittest.cc
index 9d8ceb6..cc659e6 100644
--- a/chrome/browser/debugger/devtools_sanity_unittest.cc
+++ b/chrome/browser/debugger/devtools_sanity_unittest.cc
@@ -21,20 +21,23 @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
-#include "content/browser/debugger/devtools_client_host.h"
-#include "content/browser/debugger/devtools_manager.h"
-#include "content/browser/debugger/worker_devtools_manager.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/worker_host/worker_process_host.h"
 #include "content/browser/worker_host/worker_service.h"
 #include "content/browser/worker_host/worker_service_observer.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_manager.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_service.h"
 #include "net/test/test_server.h"
 
 using content::BrowserThread;
+using content::DevToolsManager;
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
 
 namespace {
 
@@ -145,7 +148,9 @@ class DevToolsSanityTest : public InProcessBrowserTest {
     // UnregisterDevToolsClientHostFor may destroy window_ so store the browser
     // first.
     Browser* browser = window_->browser();
-    devtools_manager->UnregisterDevToolsClientHostFor(inspected_rvh_);
+    DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+        inspected_rvh_);
+    devtools_manager->UnregisterDevToolsClientHostFor(agent);
 
     // Wait only when DevToolsWindow has a browser. For docked DevTools, this
     // is NULL and we skip the wait.
@@ -386,12 +391,12 @@ class WorkerDevToolsSanityTest : public InProcessBrowserTest {
     window_ = DevToolsWindow::CreateDevToolsWindowForWorker(profile);
     window_->Show(DEVTOOLS_TOGGLE_ACTION_NONE);
     DevToolsAgentHost* agent_host =
-        WorkerDevToolsManager::GetDevToolsAgentHostForWorker(
+        DevToolsAgentHostRegistry::GetDevToolsAgentHostForWorker(
             worker_data->worker_process_id,
             worker_data->worker_route_id);
     DevToolsManager::GetInstance()->RegisterDevToolsClientHostFor(
         agent_host,
-        window_);
+        window_->devtools_client_host());
     RenderViewHost* client_rvh = window_->GetRenderViewHost();
     TabContents* client_contents = client_rvh->delegate()->GetAsTabContents();
     if (client_contents->IsLoading()) {
diff --git a/chrome/browser/debugger/devtools_window.cc b/chrome/browser/debugger/devtools_window.cc
index a741085..020a242 100644
--- a/chrome/browser/debugger/devtools_window.cc
+++ b/chrome/browser/debugger/devtools_window.cc
@@ -31,7 +31,6 @@
 #include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
 #include "content/browser/browsing_instance.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/in_process_webkit/session_storage_namespace.h"
 #include "content/browser/load_notification_details.h"
 #include "content/browser/renderer_host/render_view_host.h"
@@ -39,9 +38,9 @@
 #include "content/browser/tab_contents/navigation_entry.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/tab_contents/tab_contents_view.h"
-#include "content/common/devtools_messages.h"
 #include "content/public/browser/content_browser_client.h"
-#include "content/public/browser/devtools_frontend_window.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_manager.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/common/bindings_policy.h"
 #include "grit/generated_resources.h"
@@ -53,6 +52,11 @@ base::LazyInstance<DevToolsWindowList,
      g_instances = LAZY_INSTANCE_INITIALIZER;
 }  // namespace
 
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsClientHost;
+using content::DevToolsManager;
+
 const char DevToolsWindow::kDevToolsApp[] = "DevToolsApp";
 
 // static
@@ -68,9 +72,13 @@ TabContentsWrapper* DevToolsWindow::GetDevToolsContents(
   if (!inspected_tab)
     return NULL;
 
+  if (!DevToolsAgentHostRegistry::HasDevToolsAgentHost(
+      inspected_tab->render_view_host()))
+    return NULL;
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      inspected_tab->render_view_host());
   DevToolsManager* manager = DevToolsManager::GetInstance();
-  DevToolsClientHost* client_host = manager->
-      GetDevToolsClientHostFor(inspected_tab->render_view_host());
+  DevToolsClientHost* client_host = manager->GetDevToolsClientHostFor(agent);
   DevToolsWindow* window = AsDevToolsWindow(client_host);
   if (!window || !window->is_docked())
     return NULL;
@@ -95,16 +103,17 @@ DevToolsWindow* DevToolsWindow::OpenDevToolsWindowForWorker(
     Profile* profile,
     DevToolsAgentHost* worker_agent) {
   DevToolsWindow* window;
-  DevToolsClientHost* client =
-      DevToolsManager::GetInstance()->GetDevToolsClientHostFor(worker_agent);
+  DevToolsClientHost* client = content::DevToolsManager::GetInstance()->
+      GetDevToolsClientHostFor(worker_agent);
   if (client) {
     window = AsDevToolsWindow(client);
     if (!window)
       return NULL;
   } else {
     window = DevToolsWindow::CreateDevToolsWindowForWorker(profile);
-    DevToolsManager::GetInstance()->RegisterDevToolsClientHostFor(worker_agent,
-                                                                  window);
+    DevToolsManager::GetInstance()->RegisterDevToolsClientHostFor(
+        worker_agent,
+        window->frontend_host_);
   }
   window->Show(DEVTOOLS_TOGGLE_ACTION_NONE);
   return window;
@@ -133,10 +142,9 @@ DevToolsWindow* DevToolsWindow::ToggleDevToolsWindow(
 void DevToolsWindow::InspectElement(RenderViewHost* inspected_rvh,
                                     int x,
                                     int y) {
-  inspected_rvh->Send(new DevToolsAgentMsg_InspectElement(
-      inspected_rvh->routing_id(),
-      x,
-      y));
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      inspected_rvh);
+  DevToolsManager::GetInstance()->InspectElement(agent, x, y);
   // TODO(loislo): we should initiate DevTools window opening from within
   // renderer. Otherwise, we still can hit a race condition here.
   OpenDevToolsWindow(inspected_rvh);
@@ -171,18 +179,17 @@ DevToolsWindow::DevToolsWindow(TabContentsWrapper* tab_contents,
       browser_(NULL),
       docked_(docked),
       is_loaded_(false),
-      action_on_load_(DEVTOOLS_TOGGLE_ACTION_NONE) {
+      action_on_load_(DEVTOOLS_TOGGLE_ACTION_NONE),
+      frontend_host_(NULL) {
+  frontend_host_ = DevToolsClientHost::CreateDevToolsFrontendHost(
+      tab_contents->tab_contents(),
+      this);
   g_instances.Get().push_back(this);
   // Wipe out page icon so that the default application icon is used.
   NavigationEntry* entry = tab_contents_->controller().GetActiveEntry();
   entry->favicon().set_bitmap(SkBitmap());
   entry->favicon().set_is_valid(true);
 
-  // Install DevTools front-end message handler.
-  content::SetupDevToolsFrontendDelegate(
-      tab_contents->tab_contents(),
-      this);
-
   // Register on-load actions.
   registrar_.Add(
       this,
@@ -214,13 +221,6 @@ DevToolsWindow::~DevToolsWindow() {
   instances.erase(it);
 }
 
-void DevToolsWindow::SendMessageToClient(const IPC::Message& message) {
-  RenderViewHost* target_host = tab_contents_->render_view_host();
-  IPC::Message* m =  new IPC::Message(message);
-  m->set_routing_id(target_host->routing_id());
-  target_host->Send(m);
-}
-
 void DevToolsWindow::InspectedTabClosing() {
   if (docked_) {
     // Update dev tools to reflect removed dev tools window.
@@ -477,7 +477,7 @@ void DevToolsWindow::Observe(int type,
       // of window.Close event.
       // Notify manager that this DevToolsClientHost no longer exists and
       // initiate self-destuct here.
-      NotifyCloseListener();
+      DevToolsManager::GetInstance()->ClientHostClosing(frontend_host_);
       delete this;
     }
   } else if (type == chrome::NOTIFICATION_BROWSER_THEME_CHANGED) {
@@ -598,13 +598,14 @@ DevToolsWindow* DevToolsWindow::ToggleDevToolsWindow(
     RenderViewHost* inspected_rvh,
     bool force_open,
     DevToolsToggleAction action) {
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      inspected_rvh);
   DevToolsManager* manager = DevToolsManager::GetInstance();
-
-  DevToolsClientHost* host = manager->GetDevToolsClientHostFor(inspected_rvh);
+  DevToolsClientHost* host = manager->GetDevToolsClientHostFor(agent);
   DevToolsWindow* window = AsDevToolsWindow(host);
   if (host != NULL && window == NULL) {
     // Break remote debugging / extension debugging session.
-    manager->UnregisterDevToolsClientHostFor(inspected_rvh);
+    manager->UnregisterDevToolsClientHostFor(agent);
   }
 
   bool do_open = force_open;
@@ -613,7 +614,7 @@ DevToolsWindow* DevToolsWindow::ToggleDevToolsWindow(
         inspected_rvh->process()->GetBrowserContext());
     bool docked = profile->GetPrefs()->GetBoolean(prefs::kDevToolsOpenDocked);
     window = Create(profile, inspected_rvh, docked, false);
-    manager->RegisterDevToolsClientHostFor(inspected_rvh, window);
+    manager->RegisterDevToolsClientHostFor(agent, window->frontend_host_);
     do_open = true;
   }
 
@@ -622,7 +623,7 @@ DevToolsWindow* DevToolsWindow::ToggleDevToolsWindow(
   if (!window->is_docked() || do_open)
     window->Show(action);
   else
-    manager->UnregisterDevToolsClientHostFor(inspected_rvh);
+    manager->UnregisterDevToolsClientHostFor(agent);
 
   return window;
 }
@@ -635,17 +636,12 @@ DevToolsWindow* DevToolsWindow::AsDevToolsWindow(
   DevToolsWindowList& instances = g_instances.Get();
   for (DevToolsWindowList::iterator it = instances.begin();
        it != instances.end(); ++it) {
-    DevToolsClientHost* client = *it;
-    if (client == client_host)
+    if ((*it)->frontend_host_ == client_host)
       return *it;
   }
   return NULL;
 }
 
-void DevToolsWindow::ForwardToDevToolsAgent(const IPC::Message& message) {
-  DevToolsManager::GetInstance()->ForwardToDevToolsAgent(this, message);
-}
-
 void DevToolsWindow::ActivateWindow() {
   if (!docked_) {
     if (!browser_->window()->IsActive()) {
@@ -660,7 +656,7 @@ void DevToolsWindow::ActivateWindow() {
 
 void DevToolsWindow::CloseWindow() {
   DCHECK(docked_);
-  NotifyCloseListener();
+  DevToolsManager::GetInstance()->ClientHostClosing(frontend_host_);
   InspectedTabClosing();
 }
 
diff --git a/chrome/browser/debugger/devtools_window.h b/chrome/browser/debugger/devtools_window.h
index a9616e3..49c2c17 100644
--- a/chrome/browser/debugger/devtools_window.h
+++ b/chrome/browser/debugger/devtools_window.h
@@ -11,9 +11,9 @@
 
 #include "base/basictypes.h"
 #include "chrome/browser/debugger/devtools_toggle_action.h"
-#include "content/browser/debugger/devtools_client_host.h"
 #include "content/browser/tab_contents/tab_contents_delegate.h"
-#include "content/public/browser/devtools_frontend_window_delegate.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_frontend_host_delegate.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
@@ -23,7 +23,6 @@ class Message;
 
 class Browser;
 class BrowserWindow;
-class DevToolsAgentHost;
 class PrefService;
 class Profile;
 class RenderViewHost;
@@ -33,10 +32,14 @@ namespace base {
 class Value;
 }
 
-class DevToolsWindow : public DevToolsClientHost,
-                       private content::NotificationObserver,
+namespace content {
+class DevToolsAgentHost;
+class DevToolsClientHost;
+}
+
+class DevToolsWindow : private content::NotificationObserver,
                        private TabContentsDelegate,
-                       private content::DevToolsFrontendWindowDelegate {
+                       private content::DevToolsFrontendHostDelegate {
  public:
   static const char kDevToolsApp[];
   static void RegisterUserPrefs(PrefService* prefs);
@@ -45,7 +48,7 @@ class DevToolsWindow : public DevToolsClientHost,
 
   static DevToolsWindow* OpenDevToolsWindowForWorker(
       Profile* profile,
-      DevToolsAgentHost* worker_agent);
+      content::DevToolsAgentHost* worker_agent);
   static DevToolsWindow* CreateDevToolsWindowForWorker(Profile* profile);
   static DevToolsWindow* OpenDevToolsWindow(RenderViewHost* inspected_rvh);
   static DevToolsWindow* ToggleDevToolsWindow(RenderViewHost* inspected_rvh,
@@ -55,7 +58,6 @@ class DevToolsWindow : public DevToolsClientHost,
   virtual ~DevToolsWindow();
 
   // Overridden from DevToolsClientHost.
-  virtual void SendMessageToClient(const IPC::Message& message) OVERRIDE;
   virtual void InspectedTabClosing() OVERRIDE;
   virtual void TabReplaced(TabContents* new_tab) OVERRIDE;
   RenderViewHost* GetRenderViewHost();
@@ -65,6 +67,9 @@ class DevToolsWindow : public DevToolsClientHost,
   TabContentsWrapper* tab_contents() { return tab_contents_; }
   Browser* browser() { return browser_; }  // For tests.
   bool is_docked() { return docked_; }
+  content::DevToolsClientHost* devtools_client_host() {
+    return frontend_host_;
+  }
 
  private:
   static DevToolsWindow* Create(Profile* profile,
@@ -121,10 +126,9 @@ class DevToolsWindow : public DevToolsClientHost,
   static DevToolsWindow* ToggleDevToolsWindow(RenderViewHost* inspected_rvh,
                                               bool force_open,
                                               DevToolsToggleAction action);
-  static DevToolsWindow* AsDevToolsWindow(DevToolsClientHost*);
+  static DevToolsWindow* AsDevToolsWindow(content::DevToolsClientHost*);
 
   // content::DevToolsClientHandlerDelegate overrides.
-  virtual void ForwardToDevToolsAgent(const IPC::Message& message) OVERRIDE;
   virtual void ActivateWindow() OVERRIDE;
   virtual void CloseWindow() OVERRIDE;
   virtual void MoveWindow(int x, int y) OVERRIDE;
@@ -132,6 +136,7 @@ class DevToolsWindow : public DevToolsClientHost,
   virtual void UndockWindow() OVERRIDE;
   virtual void SaveToFile(const std::string& suggested_file_name,
                           const std::string& content) OVERRIDE;
+
   void RequestSetDocked(bool docked);
 
   Profile* profile_;
@@ -142,6 +147,7 @@ class DevToolsWindow : public DevToolsClientHost,
   bool is_loaded_;
   DevToolsToggleAction action_on_load_;
   content::NotificationRegistrar registrar_;
+  content::DevToolsClientHost* frontend_host_;
   DISALLOW_COPY_AND_ASSIGN(DevToolsWindow);
 };
 
diff --git a/chrome/browser/extensions/extension_debugger_api.cc b/chrome/browser/extensions/extension_debugger_api.cc
index 80d7970..c9bcb6c 100644
--- a/chrome/browser/extensions/extension_debugger_api.cc
+++ b/chrome/browser/extensions/extension_debugger_api.cc
@@ -22,13 +22,18 @@
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_error_utils.h"
-#include "content/browser/debugger/devtools_client_host.h"
-#include "content/browser/debugger/devtools_manager.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_manager.h"
 #include "content/browser/tab_contents/tab_contents.h"
-#include "content/common/devtools_messages.h"
 #include "content/public/browser/notification_source.h"
 #include "webkit/glue/webkit_glue.h"
 
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsClientHost;
+using content::DevToolsManager;
+
 namespace keys = extension_debugger_api_constants;
 
 class ExtensionDevToolsClientHost : public DevToolsClientHost,
@@ -49,7 +54,7 @@ class ExtensionDevToolsClientHost : public DevToolsClientHost,
 
   // DevToolsClientHost interface
   virtual void InspectedTabClosing();
-  virtual void SendMessageToClient(const IPC::Message& msg);
+  virtual void DispatchOnInspectorFrontend(const std::string& message);
   virtual void TabReplaced(TabContents* tab_contents);
   virtual void FrameNavigating(const std::string& url) {}
 
@@ -58,7 +63,6 @@ class ExtensionDevToolsClientHost : public DevToolsClientHost,
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details);
-  void OnDispatchOnInspectorFrontend(const std::string& data);
 
   TabContents* tab_contents_;
   std::string extension_id_;
@@ -98,8 +102,12 @@ class AttachedClientHosts {
   }
 
   ExtensionDevToolsClientHost* Lookup(RenderViewHost* rvh) {
+    if (!DevToolsAgentHostRegistry::HasDevToolsAgentHost(rvh))
+      return NULL;
+    DevToolsAgentHost* agent =
+        DevToolsAgentHostRegistry::GetDevToolsAgentHost(rvh);
     DevToolsClientHost* client_host =
-        DevToolsManager::GetInstance()->GetDevToolsClientHostFor(rvh);
+        DevToolsManager::GetInstance()->GetDevToolsClientHostFor(agent);
     std::set<DevToolsClientHost*>::iterator it =
         client_hosts_.find(client_host);
     if (it == client_hosts_.end())
@@ -130,9 +138,9 @@ ExtensionDevToolsClientHost::ExtensionDevToolsClientHost(
                  content::Source<Profile>(profile));
 
   // Attach to debugger and tell it we are ready.
-  DevToolsManager::GetInstance()->RegisterDevToolsClientHostFor(
-      tab_contents_->render_view_host(),
-      this);
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      tab_contents_->render_view_host());
+  DevToolsManager::GetInstance()->RegisterDevToolsClientHostFor(agent, this);
 }
 
 ExtensionDevToolsClientHost::~ExtensionDevToolsClientHost() {
@@ -163,22 +171,13 @@ void ExtensionDevToolsClientHost::InspectedTabClosing() {
   delete this;
 }
 
-void ExtensionDevToolsClientHost::SendMessageToClient(
-    const IPC::Message& msg) {
-  IPC_BEGIN_MESSAGE_MAP(ExtensionDevToolsClientHost, msg)
-    IPC_MESSAGE_HANDLER(DevToolsClientMsg_DispatchOnInspectorFrontend,
-                        OnDispatchOnInspectorFrontend);
-    IPC_MESSAGE_UNHANDLED_ERROR()
-  IPC_END_MESSAGE_MAP()
-}
-
 void ExtensionDevToolsClientHost::TabReplaced(
     TabContents* tab_contents) {
   tab_contents_ = tab_contents;
 }
 
 void ExtensionDevToolsClientHost::Close() {
-  DevToolsClientHost::NotifyCloseListener();
+  DevToolsManager::GetInstance()->ClientHostClosing(this);
   delete this;
 }
 
@@ -196,10 +195,7 @@ void ExtensionDevToolsClientHost::SendMessageToBackend(
 
   std::string json_args;
   base::JSONWriter::Write(&protocol_request, false, &json_args);
-  DevToolsManager::GetInstance()->ForwardToDevToolsAgent(
-      this,
-      DevToolsAgentMsg_DispatchOnInspectorBackend(MSG_ROUTING_NONE,
-                                                  json_args));
+  DevToolsManager::GetInstance()->DispatchOnInspectorBackend(this, json_args);
 }
 
 void ExtensionDevToolsClientHost::Observe(
@@ -210,14 +206,14 @@ void ExtensionDevToolsClientHost::Observe(
   Close();
 }
 
-void ExtensionDevToolsClientHost::OnDispatchOnInspectorFrontend(
-    const std::string& data) {
+void ExtensionDevToolsClientHost::DispatchOnInspectorFrontend(
+    const std::string& message) {
   Profile* profile =
       Profile::FromBrowserContext(tab_contents_->browser_context());
   if (profile == NULL || !profile->GetExtensionEventRouter())
     return;
 
-  scoped_ptr<Value> result(base::JSONReader::Read(data, false));
+  scoped_ptr<Value> result(base::JSONReader::Read(message, false));
   if (!result->IsType(Value::TYPE_DICTIONARY))
     return;
   DictionaryValue* dictionary = static_cast<DictionaryValue*>(result.get());
@@ -314,8 +310,10 @@ bool AttachDebuggerFunction::RunImpl() {
     return false;
   }
 
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      contents_->render_view_host());
   DevToolsClientHost* client_host = DevToolsManager::GetInstance()->
-      GetDevToolsClientHostFor(contents_->render_view_host());
+      GetDevToolsClientHostFor(agent);
 
   if (client_host != NULL) {
     error_ = ExtensionErrorUtils::FormatErrorMessage(
diff --git a/chrome/browser/extensions/extension_devtools_bridge.cc b/chrome/browser/extensions/extension_devtools_bridge.cc
index 5372296..237e072 100644
--- a/chrome/browser/extensions/extension_devtools_bridge.cc
+++ b/chrome/browser/extensions/extension_devtools_bridge.cc
@@ -15,9 +15,13 @@
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/tab_contents/tab_contents.h"
-#include "content/common/devtools_messages.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_manager.h"
+
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsManager;
 
 ExtensionDevToolsBridge::ExtensionDevToolsBridge(int tab_id,
                                                  Profile* profile)
@@ -56,29 +60,25 @@ bool ExtensionDevToolsBridge::RegisterAsDevToolsClientHost() {
                                    &browser, &tab_strip,
                                    &contents, &tab_index)) {
     DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
-    if (devtools_manager->GetDevToolsClientHostFor(contents->
-            render_view_host()) != NULL)
+    DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+        contents->render_view_host());
+    if (devtools_manager->GetDevToolsClientHostFor(agent))
       return false;
 
-    devtools_manager->RegisterDevToolsClientHostFor(
-        contents->render_view_host(), this);
+    devtools_manager->RegisterDevToolsClientHostFor(agent, this);
 
     // Following messages depend on inspector protocol that is not yet
     // finalized.
 
     // 1. Start timeline profiler.
-    devtools_manager->ForwardToDevToolsAgent(
+    devtools_manager->DispatchOnInspectorBackend(
         this,
-        DevToolsAgentMsg_DispatchOnInspectorBackend(
-            MSG_ROUTING_NONE,
-            FormatDevToolsMessage(2, "Timeline.start")));
+        FormatDevToolsMessage(2, "Timeline.start"));
 
     // 2. Enable network resource tracking.
-    devtools_manager->ForwardToDevToolsAgent(
+    devtools_manager->DispatchOnInspectorBackend(
         this,
-        DevToolsAgentMsg_DispatchOnInspectorBackend(
-            MSG_ROUTING_NONE,
-            FormatDevToolsMessage(3, "Network.enable")));
+        FormatDevToolsMessage(3, "Network.enable"));
 
     return true;
   }
@@ -87,8 +87,7 @@ bool ExtensionDevToolsBridge::RegisterAsDevToolsClientHost() {
 
 void ExtensionDevToolsBridge::UnregisterAsDevToolsClientHost() {
   DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
-
-  NotifyCloseListener();
+  DevToolsManager::GetInstance()->ClientHostClosing(this);
 }
 
 // If the tab we are looking at is going away then we fire a closing event at
@@ -106,20 +105,7 @@ void ExtensionDevToolsBridge::InspectedTabClosing() {
   extension_devtools_manager_->BridgeClosingForTab(tab_id_);
 }
 
-void ExtensionDevToolsBridge::SendMessageToClient(const IPC::Message& msg) {
-  IPC_BEGIN_MESSAGE_MAP(ExtensionDevToolsBridge, msg)
-    IPC_MESSAGE_HANDLER(DevToolsClientMsg_DispatchOnInspectorFrontend,
-                        OnDispatchOnInspectorFrontend);
-    IPC_MESSAGE_UNHANDLED_ERROR()
-  IPC_END_MESSAGE_MAP()
-}
-
-void ExtensionDevToolsBridge::TabReplaced(TabContents* new_tab) {
-  // We don't update the tab id as it needs to remain the same so that we can
-  // properly unregister.
-}
-
-void ExtensionDevToolsBridge::OnDispatchOnInspectorFrontend(
+void ExtensionDevToolsBridge::DispatchOnInspectorFrontend(
     const std::string& data) {
   DCHECK_EQ(MessageLoop::current()->type(), MessageLoop::TYPE_UI);
 
@@ -127,3 +113,8 @@ void ExtensionDevToolsBridge::OnDispatchOnInspectorFrontend(
   profile_->GetExtensionEventRouter()->DispatchEventToRenderers(
       on_page_event_name_, json, profile_, GURL());
 }
+
+void ExtensionDevToolsBridge::TabReplaced(TabContents* new_tab) {
+  // We don't update the tab id as it needs to remain the same so that we can
+  // properly unregister.
+}
diff --git a/chrome/browser/extensions/extension_devtools_bridge.h b/chrome/browser/extensions/extension_devtools_bridge.h
index dbcabd4..6c5c292 100644
--- a/chrome/browser/extensions/extension_devtools_bridge.h
+++ b/chrome/browser/extensions/extension_devtools_bridge.h
@@ -11,12 +11,12 @@
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/extensions/extension_devtools_manager.h"
 #include "chrome/browser/extensions/extension_message_service.h"
-#include "content/browser/debugger/devtools_client_host.h"
+#include "content/public/browser/devtools_client_host.h"
 
 class Profile;
 
 // This class is a DevToolsClientHost that fires extension events.
-class ExtensionDevToolsBridge : public DevToolsClientHost {
+class ExtensionDevToolsBridge : public content::DevToolsClientHost {
  public:
   ExtensionDevToolsBridge(int tab_id, Profile* profile);
   virtual ~ExtensionDevToolsBridge();
@@ -28,14 +28,12 @@ class ExtensionDevToolsBridge : public DevToolsClientHost {
   // closing.
   virtual void InspectedTabClosing() OVERRIDE;
 
-  // DevToolsClientHost, called to send a message to this host.
-  virtual void SendMessageToClient(const IPC::Message& msg) OVERRIDE;
+  // DevToolsClientHost, called to dispatch a message on this client.
+  virtual void DispatchOnInspectorFrontend(const std::string& message) OVERRIDE;
 
   virtual void TabReplaced(TabContents* new_tab) OVERRIDE;
 
  private:
-  void OnDispatchOnInspectorFrontend(const std::string& data);
-
   virtual void FrameNavigating(const std::string& url) OVERRIDE {}
 
   // ID of the tab we are monitoring.
diff --git a/chrome/browser/extensions/extension_devtools_browsertests.cc b/chrome/browser/extensions/extension_devtools_browsertests.cc
index 9f220b7..f41ebd3 100644
--- a/chrome/browser/extensions/extension_devtools_browsertests.cc
+++ b/chrome/browser/extensions/extension_devtools_browsertests.cc
@@ -16,14 +16,19 @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/ui_test_utils.h"
-#include "content/browser/debugger/devtools_client_host.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/site_instance.h"
 #include "content/browser/tab_contents/tab_contents.h"
-#include "content/common/devtools_messages.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_manager.h"
 #include "net/base/net_util.h"
 
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsClientHost;
+using content::DevToolsManager;
+
 // 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,
@@ -73,18 +78,16 @@ IN_PROC_BROWSER_TEST_F(ExtensionDevToolsBrowserTest, FLAKY_TimelineApi) {
 
   // Setting the events should have caused an ExtensionDevToolsBridge to be
   // registered for the tab's RenderViewHost.
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      tab_contents->render_view_host());
   DevToolsClientHost* devtools_client_host =
-      devtools_manager->GetDevToolsClientHostFor(
-          tab_contents->render_view_host());
+      devtools_manager->GetDevToolsClientHostFor(agent);
   ASSERT_TRUE(devtools_client_host);
 
   // Test onPageEvent event.
   result = false;
 
-  DevToolsClientMsg_DispatchOnInspectorFrontend pageEventMessage(
-      MSG_ROUTING_NONE,
-      "");
-  devtools_client_host->SendMessageToClient(pageEventMessage);
+  devtools_client_host->DispatchOnInspectorFrontend("");
   ASSERT_TRUE(ui_test_utils::ExecuteJavaScriptAndExtractBool(
       host->render_view_host(), L"", L"testReceivePageEvent()", &result));
   EXPECT_TRUE(result);
@@ -92,7 +95,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionDevToolsBrowserTest, FLAKY_TimelineApi) {
   // Test onTabClose event.
   result = false;
   devtools_manager->UnregisterDevToolsClientHostFor(
-      tab_contents->render_view_host());
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+          tab_contents->render_view_host()));
   ASSERT_TRUE(ui_test_utils::ExecuteJavaScriptAndExtractBool(
       host->render_view_host(), L"", L"testReceiveTabCloseEvent()", &result));
   EXPECT_TRUE(result);
@@ -132,7 +136,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionDevToolsBrowserTest, ProcessRefCounting) {
   // 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()));
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+          tab_contents->render_view_host())));
 
   // Register listeners from the second extension as well.
   std::wstring script = base::StringPrintf(L"registerListenersForTab(%d)",
@@ -148,7 +153,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionDevToolsBrowserTest, ProcessRefCounting) {
       host_one->render_view_host(), L"", L"unregisterListeners()", &result));
   EXPECT_TRUE(result);
   ASSERT_TRUE(devtools_manager->GetDevToolsClientHostFor(
-      tab_contents->render_view_host()));
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+          tab_contents->render_view_host())));
 
   // Removing the listeners from the second extension should tear the bridge
   // down.
@@ -157,5 +163,6 @@ IN_PROC_BROWSER_TEST_F(ExtensionDevToolsBrowserTest, ProcessRefCounting) {
       host_two->render_view_host(), L"", L"unregisterListeners()", &result));
   EXPECT_TRUE(result);
   ASSERT_FALSE(devtools_manager->GetDevToolsClientHostFor(
-      tab_contents->render_view_host()));
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+          tab_contents->render_view_host())));
 }
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 612ac2c..8fd7b59 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -86,11 +86,12 @@
 #include "chrome/common/extensions/extension_resource.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/plugin_process_host.h"
 #include "content/browser/plugin_service.h"
 #include "content/browser/user_metrics.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
@@ -118,6 +119,8 @@
 
 using base::Time;
 using content::BrowserThread;
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
 
 namespace errors = extension_manifest_errors;
 
@@ -607,10 +610,14 @@ void ExtensionService::ReloadExtension(const std::string& extension_id) {
     // later.
     ExtensionProcessManager* manager = profile_->GetExtensionProcessManager();
     ExtensionHost* host = manager->GetBackgroundHostForExtension(extension_id);
-    if (host) {
+    if (host && DevToolsAgentHostRegistry::HasDevToolsAgentHost(
+            host->render_view_host())) {
       // Look for an open inspector for the background page.
-      int devtools_cookie = DevToolsManager::GetInstance()->DetachClientHost(
-          host->render_view_host());
+      DevToolsAgentHost* agent =
+          DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+              host->render_view_host());
+      int devtools_cookie =
+          content::DevToolsManager::GetInstance()->DetachClientHost(agent);
       if (devtools_cookie >= 0)
         orphaned_dev_tools_[extension_id] = devtools_cookie;
     }
@@ -2297,8 +2304,10 @@ void ExtensionService::DidCreateRenderViewForBackgroundPage(
   if (iter == orphaned_dev_tools_.end())
     return;
 
-  DevToolsManager::GetInstance()->AttachClientHost(
-      iter->second, host->render_view_host());
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      host->render_view_host());
+  content::DevToolsManager::GetInstance()->AttachClientHost(iter->second,
+                                                            agent);
   orphaned_dev_tools_.erase(iter);
 }
 
diff --git a/chrome/browser/prerender/prerender_browsertest.cc b/chrome/browser/prerender/prerender_browsertest.cc
index 83043b5..035e84c 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -32,10 +32,11 @@
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
-#include "content/browser/debugger/devtools_client_host.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/tab_contents/tab_contents.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/common/url_constants.h"
 #include "grit/generated_resources.h"
@@ -45,6 +46,10 @@
 #include "ui/base/l10n/l10n_util.h"
 
 using content::BrowserThread;
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsClientHost;
+using content::DevToolsManager;
 
 // Prerender tests work as follows:
 //
@@ -395,12 +400,10 @@ class TestSafeBrowsingServiceFactory : public SafeBrowsingServiceFactory {
 class FakeDevToolsClientHost : public DevToolsClientHost {
  public:
   FakeDevToolsClientHost() {}
-  virtual ~FakeDevToolsClientHost() {
-    NotifyCloseListener();
-  }
+  virtual ~FakeDevToolsClientHost() {}
   virtual void InspectedTabClosing() OVERRIDE {}
   virtual void FrameNavigating(const std::string& url) OVERRIDE {}
-  virtual void SendMessageToClient(const IPC::Message& msg) OVERRIDE {}
+  virtual void DispatchOnInspectorFrontend(const std::string& msg) OVERRIDE {}
   virtual void TabReplaced(TabContents* new_tab) OVERRIDE {}
 };
 
@@ -1836,13 +1839,15 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest,
                        NavigateToPrerenderedPageWhenDevToolsAttached) {
   DisableJavascriptCalls();
   TabContents* tab_contents = browser()->GetSelectedTabContents();
-  RenderViewHost* inspected_rvh = tab_contents->render_view_host();
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      tab_contents->render_view_host());
   DevToolsManager* manager = DevToolsManager::GetInstance();
   FakeDevToolsClientHost client_host;
-  manager->RegisterDevToolsClientHostFor(inspected_rvh, &client_host);
+  manager->RegisterDevToolsClientHostFor(agent, &client_host);
   const char* url = "files/prerender/prerender_page.html";
   PrerenderTestURL(url, FINAL_STATUS_DEVTOOLS_ATTACHED, 1);
   NavigateToURL(url);
+  manager->ClientHostClosing(&client_host);
 }
 
 // Validate that the sessionStorage namespace remains the same when swapping
diff --git a/chrome/browser/prerender/prerender_manager.cc b/chrome/browser/prerender/prerender_manager.cc
index 8306bfb..323d202 100644
--- a/chrome/browser/prerender/prerender_manager.cc
+++ b/chrome/browser/prerender/prerender_manager.cc
@@ -35,7 +35,6 @@
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/render_messages.h"
 #include "content/browser/cancelable_request.h"
-#include "content/browser/debugger/render_view_devtools_agent_host.h"
 #include "content/browser/in_process_webkit/session_storage_namespace.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/resource_dispatcher_host.h"
@@ -43,6 +42,7 @@
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/tab_contents/tab_contents_delegate.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_source.h"
@@ -595,7 +595,7 @@ bool PrerenderManager::MaybeUsePrerenderedPage(TabContents* tab_contents,
 
   // Don't use prerendered pages if debugger is attached to the tab.
   // See http://crbug.com/98541
-  if (RenderViewDevToolsAgentHost::IsDebuggerAttached(tab_contents)) {
+  if (content::DevToolsAgentHostRegistry::IsDebuggerAttached(tab_contents)) {
     prerender_contents.release()->Destroy(FINAL_STATUS_DEVTOOLS_ATTACHED);
     return false;
   }
diff --git a/chrome/browser/task_manager/task_manager_worker_resource_provider.cc b/chrome/browser/task_manager/task_manager_worker_resource_provider.cc
index 4380ed8..734da89 100644
--- a/chrome/browser/task_manager/task_manager_worker_resource_provider.cc
+++ b/chrome/browser/task_manager/task_manager_worker_resource_provider.cc
@@ -12,11 +12,11 @@
 #include "chrome/browser/debugger/devtools_window.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "content/browser/browser_child_process_host.h"
-#include "content/browser/debugger/worker_devtools_manager.h"
 #include "content/browser/worker_host/worker_process_host.h"
 #include "content/browser/worker_host/worker_service.h"
 #include "content/browser/worker_host/worker_service_observer.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/common/process_type.h"
@@ -26,6 +26,8 @@
 #include "ui/base/resource/resource_bundle.h"
 
 using content::BrowserThread;
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
 
 // Objects of this class are created on the IO thread and then passed to the UI
 // thread where they are passed to the task manager. All methods must be called
@@ -127,7 +129,7 @@ void TaskManagerSharedWorkerResource::Inspect() const {
   if (!profile)
     return;
   DevToolsAgentHost* agent_host =
-      WorkerDevToolsManager::GetDevToolsAgentHostForWorker(
+      DevToolsAgentHostRegistry::GetDevToolsAgentHostForWorker(
           process_info_.id(),
           routing_id_);
   DevToolsWindow::OpenDevToolsWindowForWorker(profile, agent_host);
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index acffbcc..eb9a8dd 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -137,7 +137,6 @@
 #include "chrome/common/web_apps.h"
 #include "content/browser/browser_url_handler.h"
 #include "content/browser/child_process_security_policy.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/download/download_item.h"
 #include "content/browser/download/download_manager.h"
 #include "content/browser/download/save_package.h"
@@ -150,6 +149,7 @@
 #include "content/browser/tab_contents/navigation_entry.h"
 #include "content/browser/tab_contents/tab_contents_view.h"
 #include "content/browser/user_metrics.h"
+#include "content/public/browser/devtools_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/common/content_restriction.h"
@@ -3342,10 +3342,8 @@ void Browser::TabReplacedAt(TabStripModel* tab_strip_model,
         new_contents, tab_handler_->GetTabStripModel()->IsTabPinned(index));
   }
 
-  DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
-  if (devtools_manager)  // NULL in unit tests.
-    devtools_manager->TabReplaced(old_contents->tab_contents(),
-                                  new_contents->tab_contents());
+  content::DevToolsManager::GetInstance()->TabReplaced(
+      old_contents->tab_contents(), new_contents->tab_contents());
 }
 
 void Browser::TabPinnedStateChanged(TabContentsWrapper* contents, int index) {
@@ -4160,7 +4158,7 @@ void Browser::Observe(int type,
       } else if (pref_name == prefs::kDevToolsDisabled) {
         UpdateCommandsForDevTools();
         if (profile_->GetPrefs()->GetBoolean(prefs::kDevToolsDisabled))
-          DevToolsManager::GetInstance()->CloseAllClientHosts();
+          content::DevToolsManager::GetInstance()->CloseAllClientHosts();
       } else if (pref_name == prefs::kEditBookmarksEnabled) {
         UpdateCommandsForBookmarkEditing();
       } else if (pref_name == prefs::kShowBookmarkBar) {
diff --git a/chrome/browser/ui/webui/devtools_ui.cc b/chrome/browser/ui/webui/devtools_ui.cc
index 5ea6be7..0d1ae7f 100644
--- a/chrome/browser/ui/webui/devtools_ui.cc
+++ b/chrome/browser/ui/webui/devtools_ui.cc
@@ -14,8 +14,8 @@
 #include "chrome/common/url_constants.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/tab_contents/tab_contents.h"
-#include "content/common/devtools_messages.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/devtools_client_host.h"
 #include "grit/devtools_resources_map.h"
 #include "ui/base/resource/resource_bundle.h"
 
@@ -106,8 +106,6 @@ DevToolsUI::DevToolsUI(TabContents* contents) : ChromeWebUI(contents) {
 }
 
 void DevToolsUI::RenderViewCreated(RenderViewHost* render_view_host) {
-  render_view_host->Send(new DevToolsMsg_SetupDevToolsClient(
-      render_view_host->routing_id()));
-
+  content::DevToolsClientHost::SetupDevToolsFrontendClient(render_view_host);
   ChromeWebUI::RenderViewCreated(render_view_host);
 }
diff --git a/chrome/browser/ui/webui/workers_ui.cc b/chrome/browser/ui/webui/workers_ui.cc
index d8ad254..521740f 100644
--- a/chrome/browser/ui/webui/workers_ui.cc
+++ b/chrome/browser/ui/webui/workers_ui.cc
@@ -16,7 +16,7 @@
 #include "chrome/browser/ui/webui/chrome_url_data_manager_backend.h"
 #include "chrome/browser/ui/webui/chrome_web_ui_data_source.h"
 #include "chrome/common/url_constants.h"
-#include "content/browser/debugger/worker_devtools_manager.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/worker_host/worker_process_host.h"
 #include "content/browser/worker_host/worker_service.h"
@@ -27,6 +27,8 @@
 #include "ui/base/resource/resource_bundle.h"
 
 using content::BrowserThread;
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
 
 static const char kWorkersDataFile[] = "workers_data.json";
 
@@ -142,7 +144,7 @@ void WorkersDOMHandler::HandleOpenDevTools(const ListValue* args) {
   if (!profile)
     return;
   DevToolsAgentHost* agent_host =
-      WorkerDevToolsManager::GetDevToolsAgentHostForWorker(
+      DevToolsAgentHostRegistry::GetDevToolsAgentHostForWorker(
           worker_process_host_id,
           worker_route_id);
   DevToolsWindow::OpenDevToolsWindowForWorker(profile, agent_host);
diff --git a/content/browser/debugger/devtools_agent_host.cc b/content/browser/debugger/devtools_agent_host.cc
index 0d206c9..ea9d37a 100644
--- a/content/browser/debugger/devtools_agent_host.cc
+++ b/content/browser/debugger/devtools_agent_host.cc
@@ -7,6 +7,8 @@
 #include "base/basictypes.h"
 #include "content/common/devtools_messages.h"
 
+namespace content {
+
 DevToolsAgentHost::DevToolsAgentHost() : close_listener_(NULL) {
 }
 
@@ -24,6 +26,16 @@ void DevToolsAgentHost::Detach() {
   SendMessageToAgent(new DevToolsAgentMsg_Detach(MSG_ROUTING_NONE));
 }
 
+void DevToolsAgentHost::DipatchOnInspectorBackend(const std::string& message) {
+  SendMessageToAgent(new DevToolsAgentMsg_DispatchOnInspectorBackend(
+      MSG_ROUTING_NONE, message));
+}
+
+void DevToolsAgentHost::InspectElement(int x, int y) {
+  SendMessageToAgent(new DevToolsAgentMsg_InspectElement(MSG_ROUTING_NONE,
+                                                         x, y));
+}
+
 void DevToolsAgentHost::NotifyCloseListener() {
   if (close_listener_) {
     close_listener_->AgentHostClosing(this);
@@ -31,3 +43,4 @@ void DevToolsAgentHost::NotifyCloseListener() {
   }
 }
 
+}  // namespace content
diff --git a/content/browser/debugger/devtools_agent_host.h b/content/browser/debugger/devtools_agent_host.h
index fe430dd..b0621d4 100644
--- a/content/browser/debugger/devtools_agent_host.h
+++ b/content/browser/debugger/devtools_agent_host.h
@@ -14,6 +14,8 @@ namespace IPC {
 class Message;
 }
 
+namespace content {
+
 // Describes interface for managing devtools agents from the browser process.
 class CONTENT_EXPORT DevToolsAgentHost {
  public:
@@ -25,10 +27,11 @@ class CONTENT_EXPORT DevToolsAgentHost {
   };
 
   // Sends the message to the devtools agent hosted by this object.
-  virtual void SendMessageToAgent(IPC::Message* msg) = 0;
-  virtual void Attach();
-  virtual void Reattach(const std::string& saved_agent_state);
-  virtual void Detach();
+  void Attach();
+  void Reattach(const std::string& saved_agent_state);
+  void Detach();
+  void DipatchOnInspectorBackend(const std::string& message);
+  void InspectElement(int x, int y);
 
   // TODO(yurys): get rid of this method
   virtual void NotifyClientClosing() = 0;
@@ -43,9 +46,12 @@ class CONTENT_EXPORT DevToolsAgentHost {
   DevToolsAgentHost();
   virtual ~DevToolsAgentHost() {}
 
+  virtual void SendMessageToAgent(IPC::Message* msg) = 0;
   void NotifyCloseListener();
 
   CloseListener* close_listener_;
 };
 
+}  // namespace content
+
 #endif  // CONTENT_BROWSER_DEBUGGER_DEVTOOLS_AGENT_HOST_H_
diff --git a/content/browser/debugger/devtools_client_host.cc b/content/browser/debugger/devtools_client_host.cc
deleted file mode 100644
index 68fa25f..0000000
--- a/content/browser/debugger/devtools_client_host.cc
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright (c) 2011 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 "content/browser/debugger/devtools_client_host.h"
-
-#include "content/browser/debugger/devtools_manager.h"
-
-DevToolsClientHost::~DevToolsClientHost() {
-}
-
-DevToolsClientHost::DevToolsClientHost() : close_listener_(NULL) {
-}
-
-void DevToolsClientHost::ForwardToDevToolsAgent(const IPC::Message& message) {
-  DevToolsManager::GetInstance()->ForwardToDevToolsAgent(this, message);
-}
-
-void DevToolsClientHost::NotifyCloseListener() {
-  if (close_listener_) {
-    close_listener_->ClientHostClosing(this);
-    close_listener_ = NULL;
-  }
-}
diff --git a/content/browser/debugger/devtools_frontend_host.cc b/content/browser/debugger/devtools_frontend_host.cc
new file mode 100644
index 0000000..724bd30
--- /dev/null
+++ b/content/browser/debugger/devtools_frontend_host.cc
@@ -0,0 +1,112 @@
+// Copyright (c) 2011 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 "content/browser/debugger/devtools_frontend_host.h"
+
+#include "content/browser/debugger/devtools_manager_impl.h"
+#include "content/browser/renderer_host/render_view_host.h"
+#include "content/browser/tab_contents/tab_contents.h"
+#include "content/common/devtools_messages.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_frontend_host_delegate.h"
+
+namespace content {
+
+// static
+DevToolsClientHost* DevToolsClientHost::CreateDevToolsFrontendHost(
+    TabContents* client_tab_contents,
+    DevToolsFrontendHostDelegate* delegate) {
+  return new DevToolsFrontendHost(client_tab_contents, delegate);
+}
+
+// static
+void DevToolsClientHost::SetupDevToolsFrontendClient(
+    RenderViewHost* frontend_rvh) {
+  frontend_rvh->Send(new DevToolsMsg_SetupDevToolsClient(
+      frontend_rvh->routing_id()));
+}
+
+DevToolsFrontendHost::DevToolsFrontendHost(
+    TabContents* tab_contents,
+    DevToolsFrontendHostDelegate* delegate)
+    : RenderViewHostObserver(tab_contents->render_view_host()),
+      tab_contents_(tab_contents),
+      delegate_(delegate) {
+}
+
+DevToolsFrontendHost::~DevToolsFrontendHost() {
+}
+
+void DevToolsFrontendHost::DispatchOnInspectorFrontend(
+    const std::string& message) {
+  RenderViewHost* target_host = tab_contents_->render_view_host();
+  target_host->Send(new DevToolsClientMsg_DispatchOnInspectorFrontend(
+      target_host->routing_id(),
+      message));
+}
+
+void DevToolsFrontendHost::InspectedTabClosing() {
+  delegate_->InspectedTabClosing();
+}
+
+void DevToolsFrontendHost::FrameNavigating(const std::string& url) {
+  delegate_->FrameNavigating(url);
+}
+
+void DevToolsFrontendHost::TabReplaced(TabContents* new_tab) {
+  delegate_->TabReplaced(new_tab);
+}
+
+bool DevToolsFrontendHost::OnMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(DevToolsFrontendHost, message)
+    IPC_MESSAGE_HANDLER(DevToolsAgentMsg_DispatchOnInspectorBackend,
+                        OnDispatchOnInspectorBackend)
+    IPC_MESSAGE_HANDLER(DevToolsHostMsg_ActivateWindow, OnActivateWindow)
+    IPC_MESSAGE_HANDLER(DevToolsHostMsg_CloseWindow, OnCloseWindow)
+    IPC_MESSAGE_HANDLER(DevToolsHostMsg_MoveWindow, OnMoveWindow)
+    IPC_MESSAGE_HANDLER(DevToolsHostMsg_RequestDockWindow, OnRequestDockWindow)
+    IPC_MESSAGE_HANDLER(DevToolsHostMsg_RequestUndockWindow,
+                        OnRequestUndockWindow)
+    IPC_MESSAGE_HANDLER(DevToolsHostMsg_SaveAs,
+                        OnSaveAs)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void DevToolsFrontendHost::OnDispatchOnInspectorBackend(
+    const std::string& message) {
+  DevToolsManagerImpl::GetInstance()->DispatchOnInspectorBackend(this, message);
+//  delegate_->DispatchOnInspectorBackend(message);
+}
+
+void DevToolsFrontendHost::OnActivateWindow() {
+  delegate_->ActivateWindow();
+}
+
+void DevToolsFrontendHost::OnCloseWindow() {
+  delegate_->CloseWindow();
+}
+
+void DevToolsFrontendHost::OnMoveWindow(int x, int y) {
+  delegate_->MoveWindow(x, y);
+}
+
+void DevToolsFrontendHost::OnSaveAs(
+    const std::string& suggested_file_name,
+    const std::string& content) {
+  delegate_->SaveToFile(suggested_file_name, content);
+}
+
+void DevToolsFrontendHost::OnRequestDockWindow() {
+  delegate_->DockWindow();
+}
+
+void DevToolsFrontendHost::OnRequestUndockWindow() {
+  delegate_->UndockWindow();
+}
+
+}  // namespace content
diff --git a/content/browser/debugger/devtools_frontend_host.h b/content/browser/debugger/devtools_frontend_host.h
new file mode 100644
index 0000000..7dd3a91
--- /dev/null
+++ b/content/browser/debugger/devtools_frontend_host.h
@@ -0,0 +1,59 @@
+// Copyright (c) 2011 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_BROWSER_DEBUGGER_DEVTOOLS_FRONTEND_HOST_H_
+#define CONTENT_BROWSER_DEBUGGER_DEVTOOLS_FRONTEND_HOST_H_
+#pragma once
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/render_view_host_observer.h"
+
+class TabContents;
+
+namespace content {
+
+class DevToolsFrontendHostDelegate;
+
+// This class handles messages from DevToolsClient and calls corresponding
+// methods on DevToolsFrontendHostDelegate which is implemented by the
+// embedder. This allows us to avoid exposing DevTools client messages through
+// the content public API.
+class DevToolsFrontendHost : public DevToolsClientHost,
+                             public RenderViewHostObserver {
+ public:
+  DevToolsFrontendHost(TabContents* tab_contents,
+                       DevToolsFrontendHostDelegate* delegate);
+
+ private:
+  virtual ~DevToolsFrontendHost();
+
+  // DevToolsFrontendHost implementation.
+  virtual void DispatchOnInspectorFrontend(const std::string& message) OVERRIDE;
+  virtual void InspectedTabClosing() OVERRIDE;
+  virtual void FrameNavigating(const std::string& url) OVERRIDE;
+  virtual void TabReplaced(TabContents* new_tab) OVERRIDE;
+
+  // content::RenderViewHostObserver overrides.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  void OnDispatchOnInspectorBackend(const std::string& message);
+  void OnActivateWindow();
+  void OnCloseWindow();
+  void OnMoveWindow(int x, int y);
+  void OnRequestDockWindow();
+  void OnRequestUndockWindow();
+  void OnSaveAs(const std::string& file_name,
+                const std::string& content);
+
+  TabContents* tab_contents_;
+  DevToolsFrontendHostDelegate* delegate_;
+  DISALLOW_COPY_AND_ASSIGN(DevToolsFrontendHost);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEBUGGER_DEVTOOLS_FRONTEND_HOST_H_
diff --git a/content/browser/debugger/devtools_frontend_message_handler.cc b/content/browser/debugger/devtools_frontend_message_handler.cc
deleted file mode 100644
index 13b0238..0000000
--- a/content/browser/debugger/devtools_frontend_message_handler.cc
+++ /dev/null
@@ -1,80 +0,0 @@
-// Copyright (c) 2011 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 "content/browser/debugger/devtools_frontend_message_handler.h"
-
-#include "content/browser/tab_contents/tab_contents.h"
-#include "content/common/devtools_messages.h"
-#include "content/public/browser/devtools_frontend_window.h"
-#include "content/public/browser/devtools_frontend_window_delegate.h"
-
-namespace content {
-
-void SetupDevToolsFrontendDelegate(
-    TabContents* client_tab_contents,
-    DevToolsFrontendWindowDelegate* delegate) {
-  new DevToolsFrontendMessageHandler(client_tab_contents, delegate);
-}
-
-DevToolsFrontendMessageHandler::DevToolsFrontendMessageHandler(
-    TabContents* tab_contents,
-    DevToolsFrontendWindowDelegate* delegate)
-    : RenderViewHostObserver(tab_contents->render_view_host()),
-      tab_contents_(tab_contents),
-      delegate_(delegate) {
-}
-
-DevToolsFrontendMessageHandler::~DevToolsFrontendMessageHandler() {
-}
-
-bool DevToolsFrontendMessageHandler::OnMessageReceived(
-    const IPC::Message& message) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(DevToolsFrontendMessageHandler, message)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_ForwardToAgent, ForwardToDevToolsAgent)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_ActivateWindow, OnActivateWindow)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_CloseWindow, OnCloseWindow)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_MoveWindow, OnMoveWindow)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_RequestDockWindow, OnRequestDockWindow)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_RequestUndockWindow,
-                        OnRequestUndockWindow)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_SaveAs,
-                        OnSaveAs)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
-}
-
-void DevToolsFrontendMessageHandler::ForwardToDevToolsAgent(
-    const IPC::Message& message) {
-  delegate_->ForwardToDevToolsAgent(message);
-}
-
-void DevToolsFrontendMessageHandler::OnActivateWindow() {
-  delegate_->ActivateWindow();
-}
-
-void DevToolsFrontendMessageHandler::OnCloseWindow() {
-  delegate_->CloseWindow();
-}
-
-void DevToolsFrontendMessageHandler::OnMoveWindow(int x, int y) {
-  delegate_->MoveWindow(x, y);
-}
-
-void DevToolsFrontendMessageHandler::OnSaveAs(
-    const std::string& suggested_file_name,
-    const std::string& content) {
-  delegate_->SaveToFile(suggested_file_name, content);
-}
-
-void DevToolsFrontendMessageHandler::OnRequestDockWindow() {
-  delegate_->DockWindow();
-}
-
-void DevToolsFrontendMessageHandler::OnRequestUndockWindow() {
-  delegate_->UndockWindow();
-}
-
-}  // namespace content
diff --git a/content/browser/debugger/devtools_frontend_message_handler.h b/content/browser/debugger/devtools_frontend_message_handler.h
deleted file mode 100644
index 603ee10..0000000
--- a/content/browser/debugger/devtools_frontend_message_handler.h
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright (c) 2011 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_BROWSER_DEBUGGER_DEVTOOLS_FRONTEND_MESSAGE_HANDLER_H_
-#define CONTENT_BROWSER_DEBUGGER_DEVTOOLS_FRONTEND_MESSAGE_HANDLER_H_
-#pragma once
-
-#include "base/basictypes.h"
-#include "content/public/browser/render_view_host_observer.h"
-
-class TabContents;
-
-namespace content {
-
-class DevToolsFrontendWindowDelegate;
-
-// This class handles messages from DevToolsClient and calls corresponding
-// methods on DevToolsFrontendWindowDelegate which is implemented by the
-// embedder. This allows us to avoid exposing DevTools client messages through
-// the content public API.
-class DevToolsFrontendMessageHandler : public RenderViewHostObserver {
- public:
-  DevToolsFrontendMessageHandler(TabContents* tab_contents,
-                                 DevToolsFrontendWindowDelegate* delegate);
-
- private:
-  virtual ~DevToolsFrontendMessageHandler();
-
-  // content::RenderViewHostObserver overrides.
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-
-  void ForwardToDevToolsAgent(const IPC::Message& message);
-  void OnActivateWindow();
-  void OnCloseWindow();
-  void OnMoveWindow(int x, int y);
-  void OnRequestDockWindow();
-  void OnRequestUndockWindow();
-  void OnSaveAs(const std::string& file_name,
-                const std::string& content);
-
-  TabContents* tab_contents_;
-  DevToolsFrontendWindowDelegate* delegate_;
-  DISALLOW_COPY_AND_ASSIGN(DevToolsFrontendMessageHandler);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_DEBUGGER_DEVTOOLS_FRONTEND_MESSAGE_HANDLER_H_
diff --git a/content/browser/debugger/devtools_http_protocol_handler.cc b/content/browser/debugger/devtools_http_protocol_handler.cc
index 8771675..df85974 100644
--- a/content/browser/debugger/devtools_http_protocol_handler.cc
+++ b/content/browser/debugger/devtools_http_protocol_handler.cc
@@ -17,12 +17,13 @@
 #include "base/threading/thread.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
-#include "content/browser/debugger/devtools_client_host.h"
-#include "content/browser/debugger/devtools_manager.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/tab_contents/tab_contents_observer.h"
 #include "content/common/devtools_messages.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_manager.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/escape.h"
 #include "net/base/io_buffer.h"
@@ -30,6 +31,10 @@
 #include "net/url_request/url_request_context.h"
 
 using content::BrowserThread;
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsClientHost;
+using content::DevToolsManager;
 
 const int kBufferSize = 16 * 1024;
 
@@ -55,23 +60,7 @@ class DevToolsClientHostImpl : public DevToolsClientHost {
         base::Bind(&net::HttpServer::Close, server_, connection_id_));
   }
 
-  virtual void SendMessageToClient(const IPC::Message& msg) {
-    IPC_BEGIN_MESSAGE_MAP(DevToolsClientHostImpl, msg)
-      IPC_MESSAGE_HANDLER(DevToolsClientMsg_DispatchOnInspectorFrontend,
-                          OnDispatchOnInspectorFrontend);
-      IPC_MESSAGE_UNHANDLED_ERROR()
-    IPC_END_MESSAGE_MAP()
-  }
-
-  virtual void TabReplaced(TabContents* new_tab) {
-  }
-
-  void NotifyCloseListener() {
-    DevToolsClientHost::NotifyCloseListener();
-  }
- private:
-  // Message handling routines
-  void OnDispatchOnInspectorFrontend(const std::string& data) {
+  virtual void DispatchOnInspectorFrontend(const std::string& data) {
     BrowserThread::PostTask(
         BrowserThread::IO,
         FROM_HERE,
@@ -81,6 +70,10 @@ class DevToolsClientHostImpl : public DevToolsClientHost {
                    data));
   }
 
+  virtual void TabReplaced(TabContents* new_tab) {
+  }
+
+ private:
   virtual void FrameNavigating(const std::string& url) {}
   net::HttpServer* server_;
   int connection_id_;
@@ -297,8 +290,10 @@ static PageList GeneratePageList(
     if (entry == NULL || !entry->url().is_valid())
       continue;
 
+    DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+        tab_contents->render_view_host());
     DevToolsClientHost* client_host = DevToolsManager::GetInstance()->
-        GetDevToolsClientHostFor(tab_contents->render_view_host());
+        GetDevToolsClientHostFor(agent);
     PageInfo page_info;
     page_info.id = TabContentsIDHelper::GetID(tab_contents);
     page_info.attached = client_host != NULL;
@@ -368,7 +363,9 @@ void DevToolsHttpProtocolHandler::OnWebSocketRequestUI(
   }
 
   DevToolsManager* manager = DevToolsManager::GetInstance();
-  if (manager->GetDevToolsClientHostFor(tab_contents->render_view_host())) {
+  DevToolsAgentHost* agent = DevToolsAgentHostRegistry::GetDevToolsAgentHost(
+      tab_contents->render_view_host());
+  if (manager->GetDevToolsClientHostFor(agent)) {
     Send500(connection_id, "Page with given id is being inspected: " + page_id);
     return;
   }
@@ -377,9 +374,7 @@ void DevToolsHttpProtocolHandler::OnWebSocketRequestUI(
       new DevToolsClientHostImpl(server_, connection_id);
   connection_to_client_host_ui_[connection_id] = client_host;
 
-  manager->RegisterDevToolsClientHostFor(
-      tab_contents->render_view_host(),
-      client_host);
+  manager->RegisterDevToolsClientHostFor(agent, client_host);
 
   AcceptWebSocket(connection_id, request);
 }
@@ -393,9 +388,7 @@ void DevToolsHttpProtocolHandler::OnWebSocketMessageUI(
     return;
 
   DevToolsManager* manager = DevToolsManager::GetInstance();
-  manager->ForwardToDevToolsAgent(
-      it->second,
-      DevToolsAgentMsg_DispatchOnInspectorBackend(MSG_ROUTING_NONE, data));
+  manager->DispatchOnInspectorBackend(it->second, data);
 }
 
 void DevToolsHttpProtocolHandler::OnCloseUI(int connection_id) {
@@ -404,7 +397,7 @@ void DevToolsHttpProtocolHandler::OnCloseUI(int connection_id) {
   if (it != connection_to_client_host_ui_.end()) {
     DevToolsClientHostImpl* client_host =
         static_cast<DevToolsClientHostImpl*>(it->second);
-    client_host->NotifyCloseListener();
+    DevToolsManager::GetInstance()->ClientHostClosing(client_host);
     delete client_host;
     connection_to_client_host_ui_.erase(connection_id);
   }
diff --git a/content/browser/debugger/devtools_http_protocol_handler.h b/content/browser/debugger/devtools_http_protocol_handler.h
index 866f925..c25b5cd 100644
--- a/content/browser/debugger/devtools_http_protocol_handler.h
+++ b/content/browser/debugger/devtools_http_protocol_handler.h
@@ -17,9 +17,12 @@
 #include "net/server/http_server.h"
 #include "net/url_request/url_request.h"
 
-class DevToolsClientHost;
 class TabContents;
 
+namespace content {
+class DevToolsClientHost;
+}
+
 namespace net {
 class URLRequestContext;
 }
@@ -120,7 +123,7 @@ class DevToolsHttpProtocolHandler
   typedef std::map<net::URLRequest*, scoped_refptr<net::IOBuffer> >
       BuffersMap;
   BuffersMap request_to_buffer_io_;
-  typedef std::map<int, DevToolsClientHost*>
+  typedef std::map<int, content::DevToolsClientHost*>
       ConnectionToClientHostMap;
   ConnectionToClientHostMap connection_to_client_host_ui_;
   scoped_ptr<Delegate> delegate_;
diff --git a/content/browser/debugger/devtools_manager.cc b/content/browser/debugger/devtools_manager_impl.cc
index 3929ce8..554f287 100644
--- a/content/browser/debugger/devtools_manager.cc
+++ b/content/browser/debugger/devtools_manager_impl.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/browser/debugger/devtools_manager.h"
+#include "content/browser/debugger/devtools_manager_impl.h"
 
 #include <vector>
 
@@ -10,26 +10,32 @@
 #include "base/message_loop.h"
 #include "content/browser/browsing_instance.h"
 #include "content/browser/child_process_security_policy.h"
-#include "content/browser/debugger/devtools_client_host.h"
 #include "content/browser/debugger/devtools_netlog_observer.h"
 #include "content/browser/debugger/render_view_devtools_agent_host.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
 #include "googleurl/src/gurl.h"
 
-using content::BrowserThread;
+namespace content {
 
 // static
 DevToolsManager* DevToolsManager::GetInstance() {
-  return Singleton<DevToolsManager>::get();
+  return DevToolsManagerImpl::GetInstance();
 }
 
-DevToolsManager::DevToolsManager()
+// static
+DevToolsManagerImpl* DevToolsManagerImpl::GetInstance() {
+  return Singleton<DevToolsManagerImpl>::get();
+}
+
+DevToolsManagerImpl::DevToolsManagerImpl()
     : last_orphan_cookie_(0) {
 }
 
-DevToolsManager::~DevToolsManager() {
+DevToolsManagerImpl::~DevToolsManagerImpl() {
   DCHECK(agent_to_client_host_.empty());
   DCHECK(client_to_agent_host_.empty());
   // By the time we destroy devtools manager, all orphan client hosts should
@@ -37,14 +43,7 @@ DevToolsManager::~DevToolsManager() {
   DCHECK(orphan_client_hosts_.empty());
 }
 
-DevToolsClientHost* DevToolsManager::GetDevToolsClientHostFor(
-    RenderViewHost* inspected_rvh) {
-  DevToolsAgentHost* agent_host = RenderViewDevToolsAgentHost::FindFor(
-      inspected_rvh);
-  return GetDevToolsClientHostFor(agent_host);
-}
-
-DevToolsClientHost* DevToolsManager::GetDevToolsClientHostFor(
+DevToolsClientHost* DevToolsManagerImpl::GetDevToolsClientHostFor(
     DevToolsAgentHost* agent_host) {
   AgentToClientHostMap::iterator it = agent_to_client_host_.find(agent_host);
   if (it != agent_to_client_host_.end())
@@ -52,50 +51,47 @@ DevToolsClientHost* DevToolsManager::GetDevToolsClientHostFor(
   return NULL;
 }
 
-void DevToolsManager::RegisterDevToolsClientHostFor(
-    RenderViewHost* inspected_rvh,
-    DevToolsClientHost* client_host) {
-  DCHECK(!GetDevToolsClientHostFor(inspected_rvh));
-  DevToolsAgentHost* agent_host = RenderViewDevToolsAgentHost::FindFor(
-      inspected_rvh);
-  RegisterDevToolsClientHostFor(agent_host, client_host);
-}
-
-void DevToolsManager::RegisterDevToolsClientHostFor(
+void DevToolsManagerImpl::RegisterDevToolsClientHostFor(
     DevToolsAgentHost* agent_host,
     DevToolsClientHost* client_host) {
   BindClientHost(agent_host, client_host);
   agent_host->Attach();
-  client_host->set_close_listener(this);
 }
 
-bool DevToolsManager::ForwardToDevToolsAgent(DevToolsClientHost* from,
-                                             const IPC::Message& message) {
+bool DevToolsManagerImpl::DispatchOnInspectorBackend(
+    DevToolsClientHost* from,
+    const std::string& message) {
   DevToolsAgentHost* agent_host = GetAgentHost(from);
   if (!agent_host)
     return false;
 
-  agent_host->SendMessageToAgent(new IPC::Message(message));
+  agent_host->DipatchOnInspectorBackend(message);
   return true;
 }
 
-void DevToolsManager::ForwardToDevToolsClient(DevToolsAgentHost* agent_host,
-                                              const IPC::Message& message) {
+void DevToolsManagerImpl::DispatchOnInspectorFrontend(
+    DevToolsAgentHost* agent_host,
+    const std::string& message) {
   DevToolsClientHost* client_host = GetDevToolsClientHostFor(agent_host);
   if (!client_host) {
     // Client window was closed while there were messages
     // being sent to it.
     return;
   }
-  client_host->SendMessageToClient(message);
+  client_host->DispatchOnInspectorFrontend(message);
 }
 
-void DevToolsManager::SaveAgentRuntimeState(DevToolsAgentHost* agent_host,
-                                            const std::string& state) {
+void DevToolsManagerImpl::SaveAgentRuntimeState(DevToolsAgentHost* agent_host,
+                                                const std::string& state) {
   agent_runtime_states_[agent_host] = state;
 }
 
-void DevToolsManager::ClientHostClosing(DevToolsClientHost* client_host) {
+void DevToolsManagerImpl::InspectElement(DevToolsAgentHost* agent_host,
+                                         int x, int y) {
+  agent_host->InspectElement(x, y);
+}
+
+void DevToolsManagerImpl::ClientHostClosing(DevToolsClientHost* client_host) {
   DevToolsAgentHost* agent_host = GetAgentHost(client_host);
   if (!agent_host) {
     // It might be in the list of orphan client hosts, remove it from there.
@@ -114,11 +110,11 @@ void DevToolsManager::ClientHostClosing(DevToolsClientHost* client_host) {
   UnbindClientHost(agent_host, client_host);
 }
 
-void DevToolsManager::AgentHostClosing(DevToolsAgentHost* agent_host) {
+void DevToolsManagerImpl::AgentHostClosing(DevToolsAgentHost* agent_host) {
   UnregisterDevToolsClientHostFor(agent_host);
 }
 
-DevToolsAgentHost* DevToolsManager::GetAgentHost(
+DevToolsAgentHost* DevToolsManagerImpl::GetAgentHost(
     DevToolsClientHost* client_host) {
   ClientHostToInspectedRvhMap::iterator it =
       client_to_agent_host_.find(client_host);
@@ -127,14 +123,7 @@ DevToolsAgentHost* DevToolsManager::GetAgentHost(
   return NULL;
 }
 
-void DevToolsManager::UnregisterDevToolsClientHostFor(
-      RenderViewHost* inspected_rvh) {
-  DevToolsAgentHost* agent_host = RenderViewDevToolsAgentHost::FindFor(
-      inspected_rvh);
-  UnregisterDevToolsClientHostFor(agent_host);
-}
-
-void DevToolsManager::UnregisterDevToolsClientHostFor(
+void DevToolsManagerImpl::UnregisterDevToolsClientHostFor(
     DevToolsAgentHost* agent_host) {
   DevToolsClientHost* client_host = GetDevToolsClientHostFor(agent_host);
   if (!client_host)
@@ -143,9 +132,9 @@ void DevToolsManager::UnregisterDevToolsClientHostFor(
   client_host->InspectedTabClosing();
 }
 
-void DevToolsManager::OnNavigatingToPendingEntry(RenderViewHost* rvh,
-                                                 RenderViewHost* dest_rvh,
-                                                 const GURL& gurl) {
+void DevToolsManagerImpl::OnNavigatingToPendingEntry(RenderViewHost* rvh,
+                                                     RenderViewHost* dest_rvh,
+                                                     const GURL& gurl) {
   if (rvh == dest_rvh && rvh->render_view_termination_status() ==
           base::TERMINATION_STATUS_STILL_RUNNING)
     return;
@@ -154,13 +143,16 @@ void DevToolsManager::OnNavigatingToPendingEntry(RenderViewHost* rvh,
     // Navigating to URL in the inspected window.
     AttachClientHost(cookie, dest_rvh);
 
-    DevToolsClientHost* client_host = GetDevToolsClientHostFor(dest_rvh);
+    DevToolsAgentHost* dest_agent_host =
+        DevToolsAgentHostRegistry::GetDevToolsAgentHost(dest_rvh);
+    DevToolsClientHost* client_host = GetDevToolsClientHostFor(
+        dest_agent_host);
     client_host->FrameNavigating(gurl.spec());
   }
 }
 
-void DevToolsManager::OnCancelPendingNavigation(RenderViewHost* pending,
-                                                RenderViewHost* current) {
+void DevToolsManagerImpl::OnCancelPendingNavigation(RenderViewHost* pending,
+                                                    RenderViewHost* current) {
   int cookie = DetachClientHost(pending);
   if (cookie != -1) {
     // Navigating to URL in the inspected window.
@@ -168,10 +160,15 @@ void DevToolsManager::OnCancelPendingNavigation(RenderViewHost* pending,
   }
 }
 
-void DevToolsManager::TabReplaced(TabContents* old_tab,
-                                  TabContents* new_tab) {
+void DevToolsManagerImpl::TabReplaced(TabContents* old_tab,
+                                      TabContents* new_tab) {
   RenderViewHost* old_rvh = old_tab->render_view_host();
-  DevToolsClientHost* client_host = GetDevToolsClientHostFor(old_rvh);
+  if (!DevToolsAgentHostRegistry::HasDevToolsAgentHost(old_rvh))
+    return;
+
+  DevToolsAgentHost* old_agent_host =
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(old_rvh);
+  DevToolsClientHost* client_host = GetDevToolsClientHostFor(old_agent_host);
   if (!client_host)
     return;  // Didn't know about old_tab.
   int cookie = DetachClientHost(old_rvh);
@@ -182,13 +179,13 @@ void DevToolsManager::TabReplaced(TabContents* old_tab,
   AttachClientHost(cookie, new_tab->render_view_host());
 }
 
-int DevToolsManager::DetachClientHost(RenderViewHost* from_rvh) {
-  DevToolsAgentHost* agent_host = RenderViewDevToolsAgentHost::FindFor(
-      from_rvh);
+int DevToolsManagerImpl::DetachClientHost(RenderViewHost* from_rvh) {
+  DevToolsAgentHost* agent_host =
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(from_rvh);
   return DetachClientHost(agent_host);
 }
 
-int DevToolsManager::DetachClientHost(DevToolsAgentHost* agent_host) {
+int DevToolsManagerImpl::DetachClientHost(DevToolsAgentHost* agent_host) {
   DevToolsClientHost* client_host = GetDevToolsClientHostFor(agent_host);
   if (!client_host)
     return -1;
@@ -202,15 +199,15 @@ int DevToolsManager::DetachClientHost(DevToolsAgentHost* agent_host) {
   return cookie;
 }
 
-void DevToolsManager::AttachClientHost(int client_host_cookie,
-                                       RenderViewHost* to_rvh) {
-  DevToolsAgentHost* agent_host = RenderViewDevToolsAgentHost::FindFor(
-      to_rvh);
+void DevToolsManagerImpl::AttachClientHost(int client_host_cookie,
+                                           RenderViewHost* to_rvh) {
+  DevToolsAgentHost* agent_host =
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(to_rvh);
   AttachClientHost(client_host_cookie, agent_host);
 }
 
-void DevToolsManager::AttachClientHost(int client_host_cookie,
-                                       DevToolsAgentHost* agent_host) {
+void DevToolsManagerImpl::AttachClientHost(int client_host_cookie,
+                                           DevToolsAgentHost* agent_host) {
   OrphanClientHosts::iterator it = orphan_client_hosts_.find(
       client_host_cookie);
   if (it == orphan_client_hosts_.end())
@@ -225,7 +222,7 @@ void DevToolsManager::AttachClientHost(int client_host_cookie,
   orphan_client_hosts_.erase(it);
 }
 
-void DevToolsManager::BindClientHost(
+void DevToolsManagerImpl::BindClientHost(
     DevToolsAgentHost* agent_host,
     DevToolsClientHost* client_host) {
   DCHECK(agent_to_client_host_.find(agent_host) ==
@@ -248,8 +245,8 @@ void DevToolsManager::BindClientHost(
     ChildProcessSecurityPolicy::GetInstance()->GrantReadRawCookies(process_id);
 }
 
-void DevToolsManager::UnbindClientHost(DevToolsAgentHost* agent_host,
-                                       DevToolsClientHost* client_host) {
+void DevToolsManagerImpl::UnbindClientHost(DevToolsAgentHost* agent_host,
+                                           DevToolsClientHost* client_host) {
   DCHECK(agent_host);
   DCHECK(agent_to_client_host_.find(agent_host)->second ==
       client_host);
@@ -282,7 +279,7 @@ void DevToolsManager::UnbindClientHost(DevToolsAgentHost* agent_host,
   ChildProcessSecurityPolicy::GetInstance()->RevokeReadRawCookies(process_id);
 }
 
-void DevToolsManager::CloseAllClientHosts() {
+void DevToolsManagerImpl::CloseAllClientHosts() {
   std::vector<DevToolsAgentHost*> agents;
   for (AgentToClientHostMap::iterator it =
            agent_to_client_host_.begin();
@@ -294,3 +291,5 @@ void DevToolsManager::CloseAllClientHosts() {
     UnregisterDevToolsClientHostFor(*it);
   }
 }
+
+}  // namespace content
diff --git a/content/browser/debugger/devtools_manager.h b/content/browser/debugger/devtools_manager_impl.h
index f589c85..62a5a9e 100644
--- a/content/browser/debugger/devtools_manager.h
+++ b/content/browser/debugger/devtools_manager_impl.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CONTENT_BROWSER_DEBUGGER_DEVTOOLS_MANAGER_H_
-#define CONTENT_BROWSER_DEBUGGER_DEVTOOLS_MANAGER_H_
+#ifndef CONTENT_BROWSER_DEBUGGER_DEVTOOLS_MANAGER_IMPL_H_
+#define CONTENT_BROWSER_DEBUGGER_DEVTOOLS_MANAGER_IMPL_H_
 #pragma once
 
 #include <map>
@@ -12,10 +12,10 @@
 #include "base/compiler_specific.h"
 #include "base/memory/singleton.h"
 #include "content/browser/debugger/devtools_agent_host.h"
-#include "content/browser/debugger/devtools_client_host.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/devtools_client_host.h"
+#include "content/public/browser/devtools_manager.h"
 
-class DevToolsAgentHost;
 class GURL;
 class RenderViewHost;
 class TabContents;
@@ -24,35 +24,31 @@ namespace IPC {
 class Message;
 }
 
+namespace content {
+
+class DevToolsAgentHost;
+
 // This class is a singleton that manages DevToolsClientHost instances and
 // routes messages between developer tools clients and agents.
 //
 // Methods below that accept inspected RenderViewHost as a parameter are
 // just convenience methods that call corresponding methods accepting
 // DevToolAgentHost.
-class CONTENT_EXPORT DevToolsManager
-    : public DevToolsClientHost::CloseListener,
-      public DevToolsAgentHost::CloseListener {
+class CONTENT_EXPORT DevToolsManagerImpl
+    : public DevToolsAgentHost::CloseListener,
+      public DevToolsManager {
  public:
-  static DevToolsManager* GetInstance();
+  // Returns single instance of this class. The instance is destroyed on the
+  // browser main loop exit so this method MUST NOT be called after that point.
+  static DevToolsManagerImpl* GetInstance();
 
-  DevToolsManager();
-  virtual ~DevToolsManager();
+  DevToolsManagerImpl();
+  virtual ~DevToolsManagerImpl();
 
-  // Returns DevToolsClientHost registered for |inspected_rvh| or NULL if
-  // there is no alive DevToolsClientHost registered for |inspected_rvh|.
-  DevToolsClientHost* GetDevToolsClientHostFor(RenderViewHost* inspected_rvh);
-
-  // Registers new DevToolsClientHost for |inspected_rvh|. There must be no
-  // other DevToolsClientHosts registered for the RenderViewHost at the moment.
-  void RegisterDevToolsClientHostFor(RenderViewHost* inspected_rvh,
-                                     DevToolsClientHost* client_host);
-  void UnregisterDevToolsClientHostFor(RenderViewHost* inspected_rvh);
-
-  bool ForwardToDevToolsAgent(DevToolsClientHost* from,
-                              const IPC::Message& message);
-  void ForwardToDevToolsClient(DevToolsAgentHost* agent_host,
-                               const IPC::Message& message);
+  virtual bool DispatchOnInspectorBackend(DevToolsClientHost* from,
+                                          const std::string& message) OVERRIDE;
+  void DispatchOnInspectorFrontend(DevToolsAgentHost* agent_host,
+                                   const std::string& message);
 
   void SaveAgentRuntimeState(DevToolsAgentHost* agent_host,
                              const std::string& state);
@@ -67,36 +63,34 @@ class CONTENT_EXPORT DevToolsManager
 
   // Invoked when a tab is replaced by another tab. This is triggered by
   // TabStripModel::ReplaceTabContentsAt.
-  void TabReplaced(TabContents* old_tab, TabContents* new_tab);
-
-  // Detaches client host and returns cookie that can be used in
-  // AttachClientHost.
-  int DetachClientHost(RenderViewHost* from_rvh);
-
-  // Attaches orphan client host to new render view host.
-  void AttachClientHost(int client_host_cookie,
-                        RenderViewHost* to_rvh);
+  virtual void TabReplaced(TabContents* old_tab, TabContents* new_tab) OVERRIDE;
 
   // Closes all open developer tools windows.
-  void CloseAllClientHosts();
-
-  void AttachClientHost(int client_host_cookie,
-                        DevToolsAgentHost* to_agent);
-  DevToolsClientHost* GetDevToolsClientHostFor(DevToolsAgentHost* agent_host);
-  void RegisterDevToolsClientHostFor(DevToolsAgentHost* agent_host,
-                                     DevToolsClientHost* client_host);
-  void UnregisterDevToolsClientHostFor(DevToolsAgentHost* agent_host);
-  int DetachClientHost(DevToolsAgentHost* from_agent);
-
- private:
-  friend struct DefaultSingletonTraits<DevToolsManager>;
+  virtual void CloseAllClientHosts() OVERRIDE;
+
+  virtual void AttachClientHost(int client_host_cookie,
+                                DevToolsAgentHost* to_agent) OVERRIDE;
+  virtual DevToolsClientHost* GetDevToolsClientHostFor(
+      DevToolsAgentHost* agent_host) OVERRIDE;
+  virtual void RegisterDevToolsClientHostFor(
+      DevToolsAgentHost* agent_host,
+      DevToolsClientHost* client_host) OVERRIDE;
+  virtual void UnregisterDevToolsClientHostFor(
+      DevToolsAgentHost* agent_host) OVERRIDE;
+  virtual int DetachClientHost(DevToolsAgentHost* from_agent) OVERRIDE;
 
-  // DevToolsClientHost::CloseListener override.
   // This method will remove all references from the manager to the
   // DevToolsClientHost and unregister all listeners related to the
   // DevToolsClientHost.
   virtual void ClientHostClosing(DevToolsClientHost* host) OVERRIDE;
 
+  // Starts inspecting element at position (x, y) in the specified page.
+  virtual void InspectElement(DevToolsAgentHost* agent_host,
+                              int x, int y) OVERRIDE;
+
+ private:
+  friend struct DefaultSingletonTraits<DevToolsManagerImpl>;
+
   // DevToolsAgentHost::CloseListener implementation.
   virtual void AgentHostClosing(DevToolsAgentHost* host) OVERRIDE;
 
@@ -108,12 +102,20 @@ class CONTENT_EXPORT DevToolsManager
   void UnbindClientHost(DevToolsAgentHost* agent_host,
                         DevToolsClientHost* client_host);
 
+  // Detaches client host and returns cookie that can be used in
+  // AttachClientHost.
+  int DetachClientHost(RenderViewHost* from_rvh);
+
+  // Attaches orphan client host to new render view host.
+  void AttachClientHost(int client_host_cookie,
+                        RenderViewHost* to_rvh);
+
   // These two maps are for tracking dependencies between inspected tabs and
   // their DevToolsClientHosts. They are useful for routing devtools messages
   // and allow us to have at most one devtools client host per tab.
   //
-  // DevToolsManager start listening to DevToolsClientHosts when they are put
-  // into these maps and removes them when they are closing.
+  // DevToolsManagerImpl starts listening to DevToolsClientHosts when they are
+  // put into these maps and removes them when they are closing.
   typedef std::map<DevToolsAgentHost*, DevToolsClientHost*>
       AgentToClientHostMap;
   AgentToClientHostMap agent_to_client_host_;
@@ -130,7 +132,9 @@ class CONTENT_EXPORT DevToolsManager
   OrphanClientHosts orphan_client_hosts_;
   int last_orphan_cookie_;
 
-  DISALLOW_COPY_AND_ASSIGN(DevToolsManager);
+  DISALLOW_COPY_AND_ASSIGN(DevToolsManagerImpl);
 };
 
-#endif  // CONTENT_BROWSER_DEBUGGER_DEVTOOLS_MANAGER_H_
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEBUGGER_DEVTOOLS_MANAGER_IMPL_H_
diff --git a/content/browser/debugger/devtools_manager_unittest.cc b/content/browser/debugger/devtools_manager_unittest.cc
index f7daf85..ead247c 100644
--- a/content/browser/debugger/devtools_manager_unittest.cc
+++ b/content/browser/debugger/devtools_manager_unittest.cc
@@ -4,8 +4,7 @@
 
 #include "base/basictypes.h"
 #include "base/time.h"
-#include "content/browser/debugger/devtools_client_host.h"
-#include "content/browser/debugger/devtools_manager.h"
+#include "content/browser/debugger/devtools_manager_impl.h"
 #include "content/browser/debugger/render_view_devtools_agent_host.h"
 #include "content/browser/mock_content_browser_client.h"
 #include "content/browser/renderer_host/test_render_view_host.h"
@@ -13,9 +12,16 @@
 #include "content/browser/tab_contents/test_tab_contents.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/content_browser_client.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
+#include "content/public/browser/devtools_client_host.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using base::TimeDelta;
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsClientHost;
+using content::DevToolsManager;
+using content::DevToolsManagerImpl;
 
 namespace {
 
@@ -30,20 +36,20 @@ class TestDevToolsClientHost : public DevToolsClientHost {
     EXPECT_TRUE(closed_);
   }
 
-  virtual void Close() {
+  virtual void Close(DevToolsManager* manager) {
     EXPECT_FALSE(closed_);
     close_counter++;
-    NotifyCloseListener();
+    manager->ClientHostClosing(this);
     closed_ = true;
   }
   virtual void InspectedTabClosing() {
-    Close();
+    FAIL();
   }
 
   virtual void SetInspectedTabUrl(const std::string& url) {
   }
 
-  virtual void SendMessageToClient(const IPC::Message& message) {
+  virtual void DispatchOnInspectorFrontend(const std::string& message) {
     last_sent_message = &message;
   }
 
@@ -56,7 +62,7 @@ class TestDevToolsClientHost : public DevToolsClientHost {
 
   static int close_counter;
 
-  const IPC::Message* last_sent_message;
+  const std::string* last_sent_message;
 
  private:
   bool closed_;
@@ -129,42 +135,46 @@ class DevToolsManagerTest : public RenderViewHostTestHarness {
 };
 
 TEST_F(DevToolsManagerTest, OpenAndManuallyCloseDevToolsClientHost) {
-  DevToolsManager manager;
+  DevToolsManagerImpl manager;
 
-  DevToolsClientHost* host = manager.GetDevToolsClientHostFor(rvh());
+  DevToolsAgentHost* agent =
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(rvh());
+  DevToolsClientHost* host = manager.GetDevToolsClientHostFor(agent);
   EXPECT_TRUE(NULL == host);
 
   TestDevToolsClientHost client_host;
-  manager.RegisterDevToolsClientHostFor(rvh(), &client_host);
+  manager.RegisterDevToolsClientHostFor(agent, &client_host);
   // Test that just registered devtools host is returned.
-  host = manager.GetDevToolsClientHostFor(rvh());
+  host = manager.GetDevToolsClientHostFor(agent);
   EXPECT_TRUE(&client_host == host);
   EXPECT_EQ(0, TestDevToolsClientHost::close_counter);
 
   // Test that the same devtools host is returned.
-  host = manager.GetDevToolsClientHostFor(rvh());
+  host = manager.GetDevToolsClientHostFor(agent);
   EXPECT_TRUE(&client_host == host);
   EXPECT_EQ(0, TestDevToolsClientHost::close_counter);
 
-  client_host.Close();
+  client_host.Close(&manager);
   EXPECT_EQ(1, TestDevToolsClientHost::close_counter);
-  host = manager.GetDevToolsClientHostFor(rvh());
+  host = manager.GetDevToolsClientHostFor(agent);
   EXPECT_TRUE(NULL == host);
 }
 
 TEST_F(DevToolsManagerTest, ForwardMessageToClient) {
-  DevToolsManager manager;
+  DevToolsManagerImpl manager;
 
   TestDevToolsClientHost client_host;
-  manager.RegisterDevToolsClientHostFor(rvh(), &client_host);
+  DevToolsAgentHost* agent_host =
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(rvh());
+  manager.RegisterDevToolsClientHostFor(agent_host, &client_host);
   EXPECT_EQ(0, TestDevToolsClientHost::close_counter);
 
-  IPC::Message m;
-  DevToolsAgentHost* agent_host = RenderViewDevToolsAgentHost::FindFor(rvh());
-  manager.ForwardToDevToolsClient(agent_host, m);
+  std::string m = "test message";
+  agent_host = DevToolsAgentHostRegistry::GetDevToolsAgentHost(rvh());
+  manager.DispatchOnInspectorFrontend(agent_host, m);
   EXPECT_TRUE(&m == client_host.last_sent_message);
 
-  client_host.Close();
+  client_host.Close(&manager);
   EXPECT_EQ(1, TestDevToolsClientHost::close_counter);
 }
 
@@ -176,8 +186,10 @@ TEST_F(DevToolsManagerTest, NoUnresponsiveDialogInInspectedTab) {
   contents()->set_delegate(&delegate);
 
   TestDevToolsClientHost client_host;
+  DevToolsAgentHost* agent_host =
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(inspected_rvh);
   DevToolsManager::GetInstance()->
-      RegisterDevToolsClientHostFor(inspected_rvh, &client_host);
+      RegisterDevToolsClientHostFor(agent_host, &client_host);
 
   // Start with a short timeout.
   inspected_rvh->StartHangMonitorTimeout(TimeDelta::FromMilliseconds(10));
@@ -188,7 +200,7 @@ TEST_F(DevToolsManagerTest, NoUnresponsiveDialogInInspectedTab) {
   EXPECT_FALSE(delegate.renderer_unresponsive_received());
 
   // Now close devtools and check that the notification is delivered.
-  client_host.Close();
+  client_host.Close(DevToolsManager::GetInstance());
   // Start with a short timeout.
   inspected_rvh->StartHangMonitorTimeout(TimeDelta::FromMilliseconds(10));
   // Wait long enough for first timeout and see if it fired.
@@ -214,21 +226,24 @@ TEST_F(DevToolsManagerTest, ReattachOnCancelPendingNavigation) {
 
   TestDevToolsClientHost client_host;
   DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
-  devtools_manager->RegisterDevToolsClientHostFor(rvh(), &client_host);
+  devtools_manager->RegisterDevToolsClientHostFor(
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(rvh()),
+      &client_host);
 
   // Navigate to new site which should get a new RenderViewHost.
   const GURL url2("http://www.yahoo.com");
   controller().LoadURL(
       url2, GURL(), content::PAGE_TRANSITION_TYPED, std::string());
   EXPECT_TRUE(contents()->cross_navigation_pending());
-  EXPECT_EQ(&client_host,
-            devtools_manager->GetDevToolsClientHostFor(pending_rvh()));
+  EXPECT_EQ(&client_host, devtools_manager->GetDevToolsClientHostFor(
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(pending_rvh())));
 
   // Interrupt pending navigation and navigate back to the original site.
   controller().LoadURL(
       url, GURL(), content::PAGE_TRANSITION_TYPED, std::string());
   contents()->TestDidNavigate(orig_rvh, params1);
   EXPECT_FALSE(contents()->cross_navigation_pending());
-  EXPECT_EQ(&client_host, devtools_manager->GetDevToolsClientHostFor(rvh()));
-  client_host.Close();
+  EXPECT_EQ(&client_host, devtools_manager->GetDevToolsClientHostFor(
+      DevToolsAgentHostRegistry::GetDevToolsAgentHost(rvh())));
+  client_host.Close(DevToolsManager::GetInstance());
 }
diff --git a/content/browser/debugger/render_view_devtools_agent_host.cc b/content/browser/debugger/render_view_devtools_agent_host.cc
index a479b16..fd3574e 100644
--- a/content/browser/debugger/render_view_devtools_agent_host.cc
+++ b/content/browser/debugger/render_view_devtools_agent_host.cc
@@ -6,7 +6,7 @@
 
 #include "base/basictypes.h"
 #include "base/lazy_instance.h"
-#include "content/browser/debugger/devtools_manager.h"
+#include "content/browser/debugger/devtools_manager_impl.h"
 #include "content/browser/debugger/render_view_devtools_agent_host.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/browser/renderer_host/render_view_host.h"
@@ -14,9 +14,12 @@
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/common/devtools_messages.h"
 #include "content/public/browser/content_browser_client.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 
+namespace content {
+
 typedef std::map<RenderViewHost*, RenderViewDevToolsAgentHost*> Instances;
 
 namespace {
@@ -25,7 +28,9 @@ base::LazyInstance<Instances,
     g_instances = LAZY_INSTANCE_INITIALIZER;
 }  // namespace
 
-DevToolsAgentHost* RenderViewDevToolsAgentHost::FindFor(
+
+// static
+DevToolsAgentHost* DevToolsAgentHostRegistry::GetDevToolsAgentHost(
     RenderViewHost* rvh) {
   Instances::iterator it = g_instances.Get().find(rvh);
   if (it != g_instances.Get().end())
@@ -33,8 +38,17 @@ DevToolsAgentHost* RenderViewDevToolsAgentHost::FindFor(
   return new RenderViewDevToolsAgentHost(rvh);
 }
 
-bool RenderViewDevToolsAgentHost::IsDebuggerAttached(
-    TabContents* tab_contents) {
+// static
+bool DevToolsAgentHostRegistry::HasDevToolsAgentHost(RenderViewHost* rvh) {
+  if (g_instances == NULL)
+    return false;
+  Instances::iterator it = g_instances.Get().find(rvh);
+  return it != g_instances.Get().end();
+}
+
+bool DevToolsAgentHostRegistry::IsDebuggerAttached(TabContents* tab_contents) {
+  if (g_instances == NULL)
+    return false;
   DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
   if (!devtools_manager)
     return false;
@@ -86,7 +100,8 @@ bool RenderViewDevToolsAgentHost::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderViewDevToolsAgentHost, message)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_ForwardToClient, OnForwardToClient)
+    IPC_MESSAGE_HANDLER(DevToolsClientMsg_DispatchOnInspectorFrontend,
+                        OnDispatchOnInspectorFrontend)
     IPC_MESSAGE_HANDLER(DevToolsHostMsg_SaveAgentRuntimeState,
                         OnSaveAgentRuntimeState)
     IPC_MESSAGE_HANDLER(DevToolsHostMsg_ClearBrowserCache, OnClearBrowserCache)
@@ -99,12 +114,12 @@ bool RenderViewDevToolsAgentHost::OnMessageReceived(
 
 void RenderViewDevToolsAgentHost::OnSaveAgentRuntimeState(
     const std::string& state) {
-  DevToolsManager::GetInstance()->SaveAgentRuntimeState(this, state);
+  DevToolsManagerImpl::GetInstance()->SaveAgentRuntimeState(this, state);
 }
 
-void RenderViewDevToolsAgentHost::OnForwardToClient(
-    const IPC::Message& message) {
-  DevToolsManager::GetInstance()->ForwardToDevToolsClient(
+void RenderViewDevToolsAgentHost::OnDispatchOnInspectorFrontend(
+    const std::string& message) {
+  DevToolsManagerImpl::GetInstance()->DispatchOnInspectorFrontend(
       this, message);
 }
 
@@ -116,3 +131,5 @@ void RenderViewDevToolsAgentHost::OnClearBrowserCookies() {
   content::GetContentClient()->browser()->ClearCookies(render_view_host_);
 }
 
+}  // namespace content
+
diff --git a/content/browser/debugger/render_view_devtools_agent_host.h b/content/browser/debugger/render_view_devtools_agent_host.h
index ff31de9..e0cab1f 100644
--- a/content/browser/debugger/render_view_devtools_agent_host.h
+++ b/content/browser/debugger/render_view_devtools_agent_host.h
@@ -16,15 +16,15 @@
 class RenderViewHost;
 class TabContents;
 
+namespace content {
+
 class CONTENT_EXPORT RenderViewDevToolsAgentHost
     : public DevToolsAgentHost,
       private content::RenderViewHostObserver {
  public:
-  static DevToolsAgentHost* FindFor(RenderViewHost*);
-  static bool IsDebuggerAttached(TabContents*);
+  RenderViewDevToolsAgentHost(RenderViewHost*);
 
  private:
-  RenderViewDevToolsAgentHost(RenderViewHost*);
   virtual ~RenderViewDevToolsAgentHost();
 
   // DevToolsAgentHost implementation.
@@ -36,7 +36,7 @@ class CONTENT_EXPORT RenderViewDevToolsAgentHost
   virtual void RenderViewHostDestroyed(RenderViewHost* rvh) OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
-  void OnForwardToClient(const IPC::Message& message);
+  void OnDispatchOnInspectorFrontend(const std::string& message);
   void OnSaveAgentRuntimeState(const std::string& state);
   void OnClearBrowserCache();
   void OnClearBrowserCookies();
@@ -46,4 +46,6 @@ class CONTENT_EXPORT RenderViewDevToolsAgentHost
   DISALLOW_COPY_AND_ASSIGN(RenderViewDevToolsAgentHost);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_BROWSER_DEBUGGER_RENDER_VIEW_DEVTOOLS_AGENT_HOST_H_
diff --git a/content/browser/debugger/worker_devtools_manager.cc b/content/browser/debugger/worker_devtools_manager.cc
index 6d6b366..6709d75 100644
--- a/content/browser/debugger/worker_devtools_manager.cc
+++ b/content/browser/debugger/worker_devtools_manager.cc
@@ -9,12 +9,13 @@
 
 #include "base/bind.h"
 #include "content/browser/debugger/devtools_agent_host.h"
-#include "content/browser/debugger/devtools_manager.h"
+#include "content/browser/debugger/devtools_manager_impl.h"
 #include "content/browser/debugger/worker_devtools_message_filter.h"
 #include "content/browser/worker_host/worker_process_host.h"
 #include "content/browser/worker_host/worker_service.h"
 #include "content/common/devtools_messages.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_service.h"
@@ -26,6 +27,18 @@
 
 using content::BrowserThread;
 
+namespace content {
+
+// Called on the UI thread.
+// static
+DevToolsAgentHost* DevToolsAgentHostRegistry::GetDevToolsAgentHostForWorker(
+    int worker_process_id,
+    int worker_route_id) {
+  return WorkerDevToolsManager::GetDevToolsAgentHostForWorker(
+      worker_process_id,
+      worker_route_id);
+}
+
 class WorkerDevToolsManager::AgentHosts
     : private content::NotificationObserver {
 public:
@@ -165,10 +178,10 @@ class WorkerDevToolsManager::DetachedClientHosts {
       RemovePendingWorkerData(id);
       return;
     }
-    DevToolsManager::GetInstance()->ForwardToDevToolsClient(agent,
-        DevToolsClientMsg_DispatchOnInspectorFrontend(MSG_ROUTING_NONE,
-            WebKit::WebDevToolsAgent::disconnectEventAsText().utf8()));
-    int cookie = DevToolsManager::GetInstance()->DetachClientHost(agent);
+    DevToolsManagerImpl::GetInstance()->DispatchOnInspectorFrontend(
+        agent,
+        WebKit::WebDevToolsAgent::disconnectEventAsText().utf8());
+    int cookie = DevToolsManagerImpl::GetInstance()->DetachClientHost(agent);
     if (cookie == -1) {
       RemovePendingWorkerData(id);
       return;
@@ -194,7 +207,7 @@ class WorkerDevToolsManager::DetachedClientHosts {
         WorkerDevToolsManager::GetDevToolsAgentHostForWorker(
             new_id.first,
             new_id.second);
-    DevToolsManager::GetInstance()->AttachClientHost(
+    DevToolsManagerImpl::GetInstance()->AttachClientHost(
         it->second,
         agent);
     worker_id_to_cookie_.erase(it);
@@ -386,7 +399,7 @@ void WorkerDevToolsManager::RegisterDevToolsAgentHostForWorker(
 void WorkerDevToolsManager::ForwardToDevToolsClient(
     int worker_process_id,
     int worker_route_id,
-    const IPC::Message& message) {
+    const std::string& message) {
   if (FindInspectedWorker(worker_process_id, worker_route_id) ==
           inspected_workers_.end()) {
       NOTREACHED();
@@ -431,13 +444,14 @@ void WorkerDevToolsManager::ForwardToWorkerDevToolsAgent(
 void WorkerDevToolsManager::ForwardToDevToolsClientOnUIThread(
     int worker_process_id,
     int worker_route_id,
-    const IPC::Message& message) {
+    const std::string& message) {
   WorkerDevToolsAgentHost* agent_host = AgentHosts::GetAgentHost(WorkerId(
       worker_process_id,
       worker_route_id));
   if (!agent_host)
     return;
-  DevToolsManager::GetInstance()->ForwardToDevToolsClient(agent_host, message);
+  DevToolsManagerImpl::GetInstance()->DispatchOnInspectorFrontend(agent_host,
+                                                                  message);
 }
 
 // static
@@ -450,7 +464,7 @@ void WorkerDevToolsManager::SaveAgentRuntimeStateOnUIThread(
       worker_route_id));
   if (!agent_host)
     return;
-  DevToolsManager::GetInstance()->SaveAgentRuntimeState(agent_host, state);
+  DevToolsManagerImpl::GetInstance()->SaveAgentRuntimeState(agent_host, state);
 }
 
 // static
@@ -480,3 +494,5 @@ void WorkerDevToolsManager::SendResumeToWorker(const WorkerId& id) {
   if (WorkerProcessHost* process = FindWorkerProcess(id.first))
     process->Send(new DevToolsAgentMsg_ResumeWorkerContext(id.second));
 }
+
+}  // namespace
diff --git a/content/browser/debugger/worker_devtools_manager.h b/content/browser/debugger/worker_devtools_manager.h
index 228653e..9cc55e5 100644
--- a/content/browser/debugger/worker_devtools_manager.h
+++ b/content/browser/debugger/worker_devtools_manager.h
@@ -15,12 +15,14 @@
 #include "content/common/content_export.h"
 #include "content/browser/worker_host/worker_service_observer.h"
 
-class DevToolsAgentHost;
-
 namespace IPC {
 class Message;
 }
 
+namespace content {
+
+class DevToolsAgentHost;
+
 // All methods are supposed to be called on the IO thread.
 class WorkerDevToolsManager : private WorkerServiceObserver {
  public:
@@ -28,13 +30,13 @@ class WorkerDevToolsManager : private WorkerServiceObserver {
   static WorkerDevToolsManager* GetInstance();
 
   // Called on the UI thread.
-  CONTENT_EXPORT static DevToolsAgentHost* GetDevToolsAgentHostForWorker(
+  static DevToolsAgentHost* GetDevToolsAgentHostForWorker(
       int worker_process_id,
       int worker_route_id);
 
   void ForwardToDevToolsClient(int worker_process_id,
                                int worker_route_id,
-                               const IPC::Message& message);
+                               const std::string& message);
   void SaveAgentRuntimeState(int worker_process_id,
                              int worker_route_id,
                              const std::string& state);
@@ -72,7 +74,7 @@ class WorkerDevToolsManager : private WorkerServiceObserver {
   static void ForwardToDevToolsClientOnUIThread(
       int worker_process_id,
       int worker_route_id,
-      const IPC::Message& message);
+      const std::string& message);
   static void SaveAgentRuntimeStateOnUIThread(
       int worker_process_id,
       int worker_route_id,
@@ -110,4 +112,6 @@ class WorkerDevToolsManager : private WorkerServiceObserver {
   DISALLOW_COPY_AND_ASSIGN(WorkerDevToolsManager);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_BROWSER_DEBUGGER_WORKER_DEVTOOLS_MANAGER_H_
diff --git a/content/browser/debugger/worker_devtools_message_filter.cc b/content/browser/debugger/worker_devtools_message_filter.cc
index 3d1795f..6cc0bc0 100644
--- a/content/browser/debugger/worker_devtools_message_filter.cc
+++ b/content/browser/debugger/worker_devtools_message_filter.cc
@@ -9,6 +9,8 @@
 #include "content/common/devtools_messages.h"
 #include "content/common/worker_messages.h"
 
+namespace content {
+
 WorkerDevToolsMessageFilter::WorkerDevToolsMessageFilter(
     int worker_process_host_id)
     : worker_process_host_id_(worker_process_host_id),
@@ -25,7 +27,8 @@ bool WorkerDevToolsMessageFilter::OnMessageReceived(
   current_routing_id_ = message.routing_id();
   IPC_BEGIN_MESSAGE_MAP_EX(WorkerDevToolsMessageFilter, message,
                            *message_was_ok)
-    IPC_MESSAGE_HANDLER(DevToolsHostMsg_ForwardToClient, OnForwardToClient)
+    IPC_MESSAGE_HANDLER(DevToolsClientMsg_DispatchOnInspectorFrontend,
+                        OnDispatchOnInspectorFrontend)
     IPC_MESSAGE_HANDLER(DevToolsHostMsg_SaveAgentRuntimeState,
                         OnSaveAgentRumtimeState)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ -33,10 +36,10 @@ bool WorkerDevToolsMessageFilter::OnMessageReceived(
   return handled;
 }
 
-void WorkerDevToolsMessageFilter::OnForwardToClient(
-    const IPC::Message& message) {
+void WorkerDevToolsMessageFilter::OnDispatchOnInspectorFrontend(
+    const std::string& message) {
   WorkerDevToolsManager::GetInstance()->ForwardToDevToolsClient(
-      worker_process_host_id_, message.routing_id(), message);
+      worker_process_host_id_, current_routing_id_, message);
 }
 
 void WorkerDevToolsMessageFilter::OnSaveAgentRumtimeState(
@@ -44,3 +47,5 @@ void WorkerDevToolsMessageFilter::OnSaveAgentRumtimeState(
   WorkerDevToolsManager::GetInstance()->SaveAgentRuntimeState(
       worker_process_host_id_, current_routing_id_, state);
 }
+
+}  // namespace content
diff --git a/content/browser/debugger/worker_devtools_message_filter.h b/content/browser/debugger/worker_devtools_message_filter.h
index 23cd549..bfa96bd 100644
--- a/content/browser/debugger/worker_devtools_message_filter.h
+++ b/content/browser/debugger/worker_devtools_message_filter.h
@@ -9,6 +9,8 @@
 #include "base/callback_forward.h"
 #include "content/browser/browser_message_filter.h"
 
+namespace content {
+
 class WorkerDevToolsMessageFilter : public BrowserMessageFilter {
  public:
   explicit WorkerDevToolsMessageFilter(int worker_process_host_id);
@@ -20,7 +22,7 @@ class WorkerDevToolsMessageFilter : public BrowserMessageFilter {
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok) OVERRIDE;
   // Message handlers.
-  void OnForwardToClient(const IPC::Message& message);
+  void OnDispatchOnInspectorFrontend(const std::string& message);
   void OnSaveAgentRumtimeState(const std::string& state);
 
   int worker_process_host_id_;
@@ -29,4 +31,6 @@ class WorkerDevToolsMessageFilter : public BrowserMessageFilter {
   DISALLOW_COPY_AND_ASSIGN(WorkerDevToolsMessageFilter);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_BROWSER_DEBUGGER_WORKER_DEVTOOLS_MESSAGE_FILTER_H_
diff --git a/content/browser/tab_contents/render_view_host_manager.cc b/content/browser/tab_contents/render_view_host_manager.cc
index 2aacafc..f2d72a3 100644
--- a/content/browser/tab_contents/render_view_host_manager.cc
+++ b/content/browser/tab_contents/render_view_host_manager.cc
@@ -6,7 +6,7 @@
 
 #include "base/command_line.h"
 #include "base/logging.h"
-#include "content/browser/debugger/devtools_manager.h"
+#include "content/browser/debugger/devtools_manager_impl.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/render_view_host_delegate.h"
 #include "content/browser/renderer_host/render_view_host_factory.h"
@@ -753,11 +753,9 @@ void RenderViewHostManager::CancelPending() {
   RenderViewHost* pending_render_view_host = pending_render_view_host_;
   pending_render_view_host_ = NULL;
 
-  DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
-  if (devtools_manager) {  // NULL in unit tests.
-      devtools_manager->OnCancelPendingNavigation(pending_render_view_host,
-                                                  render_view_host_);
-  }
+  content::DevToolsManagerImpl::GetInstance()->OnCancelPendingNavigation(
+      pending_render_view_host,
+      render_view_host_);
 
   // We no longer need to prevent the process from exiting.
   pending_render_view_host->process()->RemovePendingView();
diff --git a/content/browser/tab_contents/tab_contents.cc b/content/browser/tab_contents/tab_contents.cc
index f7fa51e..f3359a9 100644
--- a/content/browser/tab_contents/tab_contents.cc
+++ b/content/browser/tab_contents/tab_contents.cc
@@ -15,7 +15,7 @@
 #include "base/utf_string_conversions.h"
 #include "content/browser/browser_context.h"
 #include "content/browser/child_process_security_policy.h"
-#include "content/browser/debugger/devtools_manager.h"
+#include "content/browser/debugger/devtools_manager_impl.h"
 #include "content/browser/download/download_manager.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/host_zoom_map.h"
@@ -41,7 +41,7 @@
 #include "content/common/intents_messages.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/content_browser_client.h"
-#include "content/public/browser/navigation_type.h"
+#include "content/public/browser/devtools_agent_host_registry.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/common/bindings_policy.h"
 #include "content/public/common/content_constants.h"
@@ -106,6 +106,10 @@
 // replaced it, yet. Therefore, we cancel the pending RVH and skip the unloading
 // of the old RVH.
 
+using content::DevToolsAgentHost;
+using content::DevToolsAgentHostRegistry;
+using content::DevToolsManagerImpl;
+
 namespace {
 
 // Amount of time we wait between when a key event is received and the renderer
@@ -614,12 +618,10 @@ bool TabContents::NavigateToEntry(
         is_allowed_in_web_ui_renderer);
 
   // Tell DevTools agent that it is attached prior to the navigation.
-  DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
-  if (devtools_manager) {  // NULL in unit tests.
-    devtools_manager->OnNavigatingToPendingEntry(render_view_host(),
-                                                 dest_render_view_host,
-                                                 entry.url());
-  }
+  DevToolsManagerImpl::GetInstance()->OnNavigatingToPendingEntry(
+      render_view_host(),
+      dest_render_view_host,
+      entry.url());
 
   // Used for page load time metrics.
   current_load_start_ = base::TimeTicks::Now();
@@ -1892,9 +1894,10 @@ void TabContents::RendererUnresponsive(RenderViewHost* rvh,
   // Ignore renderer unresponsive event if debugger is attached to the tab
   // since the event may be a result of the renderer sitting on a breakpoint.
   // See http://crbug.com/65458
-  DevToolsManager* devtools_manager = DevToolsManager::GetInstance();
-  if (devtools_manager &&
-      devtools_manager->GetDevToolsClientHostFor(rvh) != NULL)
+  DevToolsAgentHost* agent =
+      content::DevToolsAgentHostRegistry::GetDevToolsAgentHost(rvh);
+  if (agent &&
+      DevToolsManagerImpl::GetInstance()->GetDevToolsClientHostFor(agent))
     return;
 
   if (is_during_unload) {
diff --git a/content/browser/worker_host/worker_process_host.cc b/content/browser/worker_host/worker_process_host.cc
index 79f0dc2..ba29447 100644
--- a/content/browser/worker_host/worker_process_host.cc
+++ b/content/browser/worker_host/worker_process_host.cc
@@ -259,7 +259,7 @@ void WorkerProcessHost::CreateMessageFilters(int render_process_id) {
       new SocketStreamDispatcherHost(
           new URLRequestContextSelector(request_context), resource_context_);
   AddFilter(socket_stream_dispatcher_host);
-  AddFilter(new WorkerDevToolsMessageFilter(id()));
+  AddFilter(new content::WorkerDevToolsMessageFilter(id()));
 }
 
 void WorkerProcessHost::CreateWorker(const WorkerInstance& instance) {
diff --git a/content/common/devtools_messages.h b/content/common/devtools_messages.h
index 36c88c0..6f29c0e 100644
--- a/content/common/devtools_messages.h
+++ b/content/common/devtools_messages.h
@@ -100,16 +100,6 @@ IPC_MESSAGE_ROUTED0(DevToolsMsg_SetupDevToolsClient)
 //-----------------------------------------------------------------------------
 // These are messages sent from the renderer to the browser.
 
-// Wraps an IPC message that's destined to the DevToolsClient on
-// DevToolsAgent->browser hop.
-IPC_MESSAGE_ROUTED1(DevToolsHostMsg_ForwardToClient,
-                    IPC::Message /* one of DevToolsClientMsg_XXX types */)
-
-// Wraps an IPC message that's destined to the DevToolsAgent on
-// DevToolsClient->browser hop.
-IPC_MESSAGE_ROUTED1(DevToolsHostMsg_ForwardToAgent,
-                    IPC::Message /* one of DevToolsAgentMsg_XXX types */)
-
 // Activates (brings to the front) corresponding dev tools window.
 IPC_MESSAGE_ROUTED0(DevToolsHostMsg_ActivateWindow)
 
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 754db1d..1256bfb 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -30,9 +30,11 @@
     'public/browser/browser_thread_delegate.h',
     'public/browser/content_browser_client.h',
     'public/browser/content_ipc_logging.h',
-    'public/browser/download_manager_delegate.h',
-    'public/browser/devtools_frontend_window.h',
+    'public/browser/devtools_agent_host_registry.h',
+    'public/browser/devtools_client_host.h',
     'public/browser/devtools_frontend_window_delegate.h',
+    'public/browser/devtools_manager.h',
+    'public/browser/download_manager_delegate.h',
     'public/browser/native_web_keyboard_event.h',
     'public/browser/navigation_type.h',
     'public/browser/notification_details.h',
@@ -105,14 +107,12 @@
     'browser/cross_site_request_manager.h',
     'browser/debugger/devtools_agent_host.cc',
     'browser/debugger/devtools_agent_host.h',
-    'browser/debugger/devtools_client_host.cc',
-    'browser/debugger/devtools_client_host.h',
-    'browser/debugger/devtools_frontend_message_handler.cc',
-    'browser/debugger/devtools_frontend_message_handler.h',
+    'browser/debugger/devtools_frontend_host.cc',
+    'browser/debugger/devtools_frontend_host.h',
     'browser/debugger/devtools_http_protocol_handler.cc',
     'browser/debugger/devtools_http_protocol_handler.h',
-    'browser/debugger/devtools_manager.cc',
-    'browser/debugger/devtools_manager.h',
+    'browser/debugger/devtools_manager_impl.cc',
+    'browser/debugger/devtools_manager_impl.h',
     'browser/debugger/devtools_netlog_observer.cc',
     'browser/debugger/devtools_netlog_observer.h',
     'browser/debugger/render_view_devtools_agent_host.cc',
diff --git a/content/public/browser/devtools_agent_host_registry.h b/content/public/browser/devtools_agent_host_registry.h
new file mode 100644
index 0000000..567d32e
--- /dev/null
+++ b/content/public/browser/devtools_agent_host_registry.h
@@ -0,0 +1,39 @@
+// Copyright (c) 2011 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_PUBLIC_BROWSER_DEVTOOLS_AGENT_HOST_REGISTRY_H_
+#define CONTENT_PUBLIC_BROWSER_DEVTOOLS_AGENT_HOST_REGISTRY_H_
+#pragma once
+
+#include "content/common/content_export.h"
+
+class RenderViewHost;
+class TabContents;
+
+namespace content {
+
+class DevToolsAgentHost;
+
+class CONTENT_EXPORT DevToolsAgentHostRegistry {
+ public:
+  // Returns DevToolsAgentHost that can be used for inspecting |rvh|.
+  // New DevToolsAgentHost will be created if it does not exist.
+  static DevToolsAgentHost* GetDevToolsAgentHost(RenderViewHost* rvh);
+
+  // Returns true iff an instance of DevToolsAgentHost for the |rvh|
+  // does exist.
+  static bool HasDevToolsAgentHost(RenderViewHost* rvh);
+
+  // Returns DevToolsAgentHost that can be used for inspecting shared worker
+  // with given worker process host id and routing id.
+  static DevToolsAgentHost* GetDevToolsAgentHostForWorker(
+      int worker_process_id,
+      int worker_route_id);
+
+  static bool IsDebuggerAttached(TabContents* tab_contents);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_AGENT_HOST_REGISTRY_H_
diff --git a/content/browser/debugger/devtools_client_host.h b/content/public/browser/devtools_client_host.h
index 0ae8c1b..8bd98e8 100644
--- a/content/browser/debugger/devtools_client_host.h
+++ b/content/public/browser/devtools_client_host.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CONTENT_BROWSER_DEBUGGER_DEVTOOLS_CLIENT_HOST_H_
-#define CONTENT_BROWSER_DEBUGGER_DEVTOOLS_CLIENT_HOST_H_
+#ifndef CONTENT_PUBLIC_BROWSER_DEVTOOLS_CLIENT_HOST_H_
+#define CONTENT_PUBLIC_BROWSER_DEVTOOLS_CLIENT_HOST_H_
 #pragma once
 
 #include <string>
@@ -15,23 +15,22 @@ namespace IPC {
 class Message;
 }
 
+class RenderViewHost;
 class TabContents;
 
+namespace content {
+
+class DevToolsFrontendHostDelegate;
+
 // Describes interface for managing devtools clients from browser process. There
 // are currently two types of clients: devtools windows and TCP socket
 // debuggers.
 class CONTENT_EXPORT DevToolsClientHost {
  public:
-  class CONTENT_EXPORT CloseListener {
-   public:
-    CloseListener() {}
-    virtual ~CloseListener() {}
-    virtual void ClientHostClosing(DevToolsClientHost* host) = 0;
-   private:
-    DISALLOW_COPY_AND_ASSIGN(CloseListener);
-  };
+  virtual ~DevToolsClientHost() {}
 
-  virtual ~DevToolsClientHost();
+  // Dispatches given message on the front-end.
+  virtual void DispatchOnInspectorFrontend(const std::string& message) = 0;
 
   // This method is called when tab inspected by this devtools client is
   // closing.
@@ -41,29 +40,20 @@ class CONTENT_EXPORT DevToolsClientHost {
   // navigating to |url|.
   virtual void FrameNavigating(const std::string& url) = 0;
 
-  // Sends the message to the devtools client hosted by this object.
-  virtual void SendMessageToClient(const IPC::Message& msg) = 0;
-
-  void set_close_listener(CloseListener* listener) {
-    close_listener_ = listener;
-  }
-
   // Invoked when a tab is replaced by another tab. This is triggered by
   // TabStripModel::ReplaceTabContentsAt.
   virtual void TabReplaced(TabContents* new_tab) = 0;
 
- protected:
-  DevToolsClientHost();
+  // Creates DevToolsClientHost for TabContents containing default DevTools
+  // frontend implementation.
+  static DevToolsClientHost* CreateDevToolsFrontendHost(
+      TabContents* client_tab_contents,
+      DevToolsFrontendHostDelegate* delegate);
 
-  void ForwardToDevToolsAgent(const IPC::Message& message);
-
-  // Should be called when the devtools client is going to die and this
-  // DevToolsClientHost should not be used anymore.
-  void NotifyCloseListener();
-
- private:
-  CloseListener* close_listener_;
-  DISALLOW_COPY_AND_ASSIGN(DevToolsClientHost);
+  // Sets up DevToolsClient on the corresponding RenderView.
+  static void SetupDevToolsFrontendClient(RenderViewHost* frontend_rvh);
 };
 
-#endif  // CONTENT_BROWSER_DEBUGGER_DEVTOOLS_CLIENT_HOST_H_
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_CLIENT_HOST_H_
diff --git a/content/public/browser/devtools_frontend_window_delegate.h b/content/public/browser/devtools_frontend_host_delegate.h
index 06463ee..b645bf1 100644
--- a/content/public/browser/devtools_frontend_window_delegate.h
+++ b/content/public/browser/devtools_frontend_host_delegate.h
@@ -2,27 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_WINDOW_DELEGATE_H_
-#define CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_WINDOW_DELEGATE_H_
+#ifndef CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_HOST_DELEGATE_H_
+#define CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_HOST_DELEGATE_H_
 #pragma once
 
 #include <string>
 
-namespace IPC {
-class Message;
-}
-
 namespace content {
 
 // Clients that want to use default DevTools front-end implementation should
 // implement this interface to provide access to the embedding browser from
 // the front-end.
-class DevToolsFrontendWindowDelegate {
+class DevToolsFrontendHostDelegate {
  public:
-  virtual ~DevToolsFrontendWindowDelegate() {}
-
-  // Routes message to the corresponding agent.
-  virtual void ForwardToDevToolsAgent(const IPC::Message& message) = 0;
+  virtual ~DevToolsFrontendHostDelegate() {}
 
   // Should bring DevTools window to front.
   virtual void ActivateWindow() = 0;
@@ -43,8 +36,21 @@ class DevToolsFrontendWindowDelegate {
   // Shows "Save As..." dialog to save |content|.
   virtual void SaveToFile(const std::string& suggested_file_name,
                           const std::string& content) = 0;
+
+
+  // This method is called when tab inspected by this devtools frontend is
+  // closing.
+  virtual void InspectedTabClosing() = 0;
+
+  // This method is called when tab inspected by this devtools frontend is
+  // navigating to |url|.
+  virtual void FrameNavigating(const std::string& url) = 0;
+
+  // Invoked when tab inspected by this devtools frontend is replaced by
+  // another tab. This is triggered by TabStripModel::ReplaceTabContentsAt.
+  virtual void TabReplaced(TabContents* new_tab) = 0;
 };
 
 }  // namespace content
 
-#endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_WINDOW_DELEGATE_H_
+#endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_HOST_DELEGATE_H_
diff --git a/content/public/browser/devtools_frontend_window.h b/content/public/browser/devtools_frontend_window.h
deleted file mode 100644
index 6b54ba4..0000000
--- a/content/public/browser/devtools_frontend_window.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright (c) 2011 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_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_WINDOW_H_
-#define CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_WINDOW_H_
-#pragma once
-
-class TabContents;
-
-namespace content {
-
-class DevToolsFrontendWindowDelegate;
-
-// Installs delegate for DevTools front-end loaded into |client_tab_contents|.
-CONTENT_EXPORT void SetupDevToolsFrontendDelegate(
-    TabContents* client_tab_contents,
-    DevToolsFrontendWindowDelegate* delegate);
-
-}
-
-#endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_FRONTEND_WINDOW_H_
diff --git a/content/public/browser/devtools_manager.h b/content/public/browser/devtools_manager.h
new file mode 100644
index 0000000..d2f1667
--- /dev/null
+++ b/content/public/browser/devtools_manager.h
@@ -0,0 +1,79 @@
+// Copyright (c) 2011 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_PUBLIC_BROWSER_DEVTOOLS_MANAGER_H_
+#define CONTENT_PUBLIC_BROWSER_DEVTOOLS_MANAGER_H_
+#pragma once
+
+#include <string>
+
+#include "content/common/content_export.h"
+
+class TabContents;
+
+namespace IPC {
+class Message;
+}
+
+namespace content {
+
+class DevToolsAgentHost;
+class DevToolsClientHost;
+
+// DevToolsManager connects a devtools client to inspected agent and routes
+// devtools messages between the inspected instance represented by the agent
+// and devtools front-end represented by the client. If inspected agent
+// gets terminated DevToolsManager will notify corresponding client and
+// remove it from the map.
+class CONTENT_EXPORT DevToolsManager {
+ public:
+  static DevToolsManager* GetInstance();
+
+  // Routes devtools message from |from| client to corresponding
+  // DevToolsAgentHost.
+  virtual bool DispatchOnInspectorBackend(DevToolsClientHost* from,
+                                          const std::string& message) = 0;
+
+  // Invoked when a tab is replaced by another tab. This is triggered by
+  // TabStripModel::ReplaceTabContentsAt.
+  virtual void TabReplaced(TabContents* old_tab, TabContents* new_tab) = 0;
+
+  // Closes all open developer tools windows.
+  virtual void CloseAllClientHosts() = 0;
+
+  // Returns client attached to the |agent_host| if there is one.
+  virtual DevToolsClientHost* GetDevToolsClientHostFor(
+      DevToolsAgentHost* agent_host) = 0;
+
+  // Registers new DevToolsClientHost for inspected |agent_host|. There must be
+  // no other DevToolsClientHosts registered for the |agent_host| at the moment.
+  virtual void RegisterDevToolsClientHostFor(
+      DevToolsAgentHost* agent_host,
+      DevToolsClientHost* client_host) = 0;
+  // Unregisters given |agent_host|. DevToolsManager will notify corresponding
+  // client if one is attached.
+  virtual void UnregisterDevToolsClientHostFor(
+      DevToolsAgentHost* agent_host) = 0;
+
+  // Detaches client from |from_agent| and returns a cookie that allows to
+  // reattach that client to another agent later. Returns -1 if there is no
+  // client attached to |from_agent|.
+  virtual int DetachClientHost(DevToolsAgentHost* from_agent) = 0;
+  // Reattaches client host detached with DetachClientHost method above
+  // to |to_agent|.
+  virtual void AttachClientHost(int client_host_cookie,
+                                DevToolsAgentHost* to_agent) = 0;
+
+  // This method will remove all references from the manager to the
+  // DevToolsClientHost and unregister all listeners related to the
+  // DevToolsClientHost. Called by closing client.
+  virtual void ClientHostClosing(DevToolsClientHost* client_host) = 0;
+
+  // Starts inspecting element at position (x, y) in the specified page.
+  virtual void InspectElement(DevToolsAgentHost* agent_host, int x, int y) = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_MANAGER_H_
diff --git a/content/renderer/devtools_agent.cc b/content/renderer/devtools_agent.cc
index 093011c..7843fc6 100644
--- a/content/renderer/devtools_agent.cc
+++ b/content/renderer/devtools_agent.cc
@@ -92,10 +92,8 @@ bool DevToolsAgent::OnMessageReceived(const IPC::Message& message) {
 
 void DevToolsAgent::sendMessageToInspectorFrontend(
     const WebKit::WebString& message) {
-  Send(new DevToolsHostMsg_ForwardToClient(
-      routing_id(),
-      DevToolsClientMsg_DispatchOnInspectorFrontend(MSG_ROUTING_NONE,
-                                                    message.utf8())));
+  Send(new DevToolsClientMsg_DispatchOnInspectorFrontend(routing_id(),
+                                                         message.utf8()));
 }
 
 int DevToolsAgent::hostIdentifier() {
diff --git a/content/renderer/devtools_client.cc b/content/renderer/devtools_client.cc
index 961c149..73731fe 100644
--- a/content/renderer/devtools_client.cc
+++ b/content/renderer/devtools_client.cc
@@ -32,10 +32,6 @@ DevToolsClient::DevToolsClient(RenderViewImpl* render_view)
 DevToolsClient::~DevToolsClient() {
 }
 
-void DevToolsClient::SendToAgent(const IPC::Message& tools_agent_message) {
-  Send(new DevToolsHostMsg_ForwardToAgent(routing_id(), tools_agent_message));
-}
-
 bool DevToolsClient::OnMessageReceived(const IPC::Message& message) {
   DCHECK(RenderThreadImpl::current());
 
@@ -50,8 +46,8 @@ bool DevToolsClient::OnMessageReceived(const IPC::Message& message) {
 }
 
 void DevToolsClient::sendMessageToBackend(const WebString& message)  {
-  SendToAgent(DevToolsAgentMsg_DispatchOnInspectorBackend(MSG_ROUTING_NONE,
-                                                          message.utf8()));
+  Send(new DevToolsAgentMsg_DispatchOnInspectorBackend(routing_id(),
+                                                       message.utf8()));
 }
 
 void DevToolsClient::activateWindow() {
diff --git a/content/renderer/devtools_client.h b/content/renderer/devtools_client.h
index 8dedfd6..a85a7d9 100644
--- a/content/renderer/devtools_client.h
+++ b/content/renderer/devtools_client.h
@@ -49,9 +49,6 @@ class DevToolsClient : public content::RenderViewObserver,
 
   void OnDispatchOnInspectorFrontend(const std::string& message);
 
-  // Sends message to DevToolsAgent.
-  void SendToAgent(const IPC::Message& tools_agent_message);
-
   scoped_ptr<WebKit::WebDevToolsFrontend> web_tools_frontend_;
 
   DISALLOW_COPY_AND_ASSIGN(DevToolsClient);
diff --git a/content/worker/shared_worker_devtools_agent.cc b/content/worker/shared_worker_devtools_agent.cc
index 702105d..9e897575 100644
--- a/content/worker/shared_worker_devtools_agent.cc
+++ b/content/worker/shared_worker_devtools_agent.cc
@@ -43,10 +43,9 @@ bool SharedWorkerDevToolsAgent::OnMessageReceived(const IPC::Message& message) {
 
 void SharedWorkerDevToolsAgent::SendDevToolsMessage(
     const WebKit::WebString& message) {
-    IPC::Message m = DevToolsClientMsg_DispatchOnInspectorFrontend(
+    Send(new DevToolsClientMsg_DispatchOnInspectorFrontend(
         route_id_,
-        message.utf8());
-    Send(new DevToolsHostMsg_ForwardToClient(route_id_, m));
+        message.utf8()));
 }
 
 void SharedWorkerDevToolsAgent::SaveDevToolsAgentState(