Extract a ProcessMap class from ExtensionProcessManager. This is a dumb data class that can be used on both the IO and UI threads to test extension/process associations.

BUG=95111,102617
TEST=Already covered by tests

Review URL: http://codereview.chromium.org/8387061

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@109194 0039d316-1c4b-4281-b951-d872f2087c98

34 files changed, 508 insertions, 420 deletions

diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 946d7dd..365b2b2 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -193,16 +193,19 @@ RenderProcessHostPrivilege GetPrivilegeRequiredByUrl(
 
 RenderProcessHostPrivilege GetProcessPrivilege(
     RenderProcessHost* process_host,
-    ExtensionProcessManager* extension_process_manager) {
-  if (!extension_process_manager->IsExtensionProcess(process_host->id()))
+    extensions::ProcessMap* process_map,
+    ExtensionService* service) {
+  // TODO(aa): It seems like hosted apps should be grouped separately from
+  // extensions: crbug.com/102533.
+  std::set<std::string> extension_ids =
+      process_map->GetExtensionsInProcess(process_host->id());
+  if (extension_ids.empty())
     return PRIV_NORMAL;
 
-  std::set<const Extension*> extensions_for_process(
-      extension_process_manager->GetExtensionsForProcess(process_host->id()));
-  for (std::set<const Extension*>::iterator iter =
-           extensions_for_process.begin();
-       iter != extensions_for_process.end(); ++iter) {
-    if ((*iter)->is_storage_isolated())
+  for (std::set<std::string>::iterator iter = extension_ids.begin();
+       iter != extension_ids.end(); ++iter) {
+    const Extension* extension = service->GetExtensionById(*iter, false);
+    if (extension && extension->is_storage_isolated())
       return PRIV_ISOLATED;
   }
 
@@ -396,13 +399,12 @@ bool ChromeContentBrowserClient::IsSuitableHost(
     const GURL& site_url) {
   Profile* profile =
       Profile::FromBrowserContext(process_host->browser_context());
-  ExtensionProcessManager* extension_process_manager =
-      profile->GetExtensionProcessManager();
   ExtensionService* service = profile->GetExtensionService();
+  extensions::ProcessMap* process_map = service->process_map();
 
   // These may be NULL during tests. In that case, just assume any site can
   // share any host.
-  if (!extension_process_manager || !service)
+  if (!service || !process_map)
     return true;
 
   // Experimental:
@@ -415,10 +417,65 @@ bool ChromeContentBrowserClient::IsSuitableHost(
   if (command_line.HasSwitch(switches::kEnableStrictSiteIsolation))
     return false;
 
-  return GetProcessPrivilege(process_host, extension_process_manager) ==
+  return GetProcessPrivilege(process_host, process_map, service) ==
       GetPrivilegeRequiredByUrl(site_url, service);
 }
 
+void ChromeContentBrowserClient::SiteInstanceGotProcess(
+    SiteInstance* site_instance) {
+  CHECK(site_instance->HasProcess());
+
+  Profile* profile = Profile::FromBrowserContext(
+      site_instance->browsing_instance()->browser_context());
+  ExtensionService* service = profile->GetExtensionService();
+  if (!service)
+    return;
+
+  const Extension* extension =
+      service->GetExtensionByURL(site_instance->site());
+  if (!extension)
+    extension = service->GetExtensionByWebExtent(site_instance->site());
+  if (!extension)
+    return;
+
+  service->process_map()->Insert(
+      extension->id(), site_instance->GetProcess()->id());
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&ExtensionInfoMap::RegisterExtensionProcess,
+                 profile->GetExtensionInfoMap(),
+                 extension->id(),
+                 site_instance->GetProcess()->id()));
+}
+
+void ChromeContentBrowserClient::SiteInstanceDeleting(
+    SiteInstance* site_instance) {
+  if (!site_instance->HasProcess())
+    return;
+
+  Profile* profile = Profile::FromBrowserContext(
+      site_instance->browsing_instance()->browser_context());
+  ExtensionService* service = profile->GetExtensionService();
+  if (!service)
+    return;
+
+  const Extension* extension =
+      service->GetExtensionByURL(site_instance->site());
+  if (!extension)
+    extension = service->GetExtensionByWebExtent(site_instance->site());
+  if (!extension)
+    return;
+
+  service->process_map()->Remove(
+      extension->id(), site_instance->GetProcess()->id());
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&ExtensionInfoMap::UnregisterExtensionProcess,
+                 profile->GetExtensionInfoMap(),
+                 extension->id(),
+                 site_instance->GetProcess()->id()));
+}
+
 bool ChromeContentBrowserClient::ShouldSwapProcessesForNavigation(
     const GURL& current_url,
     const GURL& new_url) {
@@ -483,13 +540,10 @@ void ChromeContentBrowserClient::AppendExtraCommandLineSwitches(
     RenderProcessHost* process = RenderProcessHost::FromID(child_process_id);
 
     Profile* profile = Profile::FromBrowserContext(process->browser_context());
-
-    ExtensionProcessManager* extension_process_manager =
-        profile->GetExtensionProcessManager();
-    if (extension_process_manager->IsExtensionProcess(
-        process->id())) {
+    extensions::ProcessMap* process_map =
+        profile->GetExtensionService()->process_map();
+    if (process_map && process_map->Contains(process->id()))
       command_line->AppendSwitch(switches::kExtensionProcess);
-    }
 
     PrefService* prefs = profile->GetPrefs();
     // Currently this pref is only registered if applied via a policy.
diff --git a/chrome/browser/chrome_content_browser_client.h b/chrome/browser/chrome_content_browser_client.h
index f978af8..14aba9d 100644
--- a/chrome/browser/chrome_content_browser_client.h
+++ b/chrome/browser/chrome_content_browser_client.h
@@ -35,6 +35,8 @@ class ChromeContentBrowserClient : public content::ContentBrowserClient {
   virtual bool IsURLSameAsAnySiteInstance(const GURL& url) OVERRIDE;
   virtual bool IsSuitableHost(RenderProcessHost* process_host,
                               const GURL& url) OVERRIDE;
+  virtual void SiteInstanceGotProcess(SiteInstance* site_instance) OVERRIDE;
+  virtual void SiteInstanceDeleting(SiteInstance* site_instance) OVERRIDE;
   virtual bool ShouldSwapProcessesForNavigation(const GURL& current_url,
                                                 const GURL& new_url) OVERRIDE;
   virtual std::string GetCanonicalEncodingNameByAliasName(
diff --git a/chrome/browser/extensions/app_process_apitest.cc b/chrome/browser/extensions/app_process_apitest.cc
index 6872c1e..75f57b5 100644
--- a/chrome/browser/extensions/app_process_apitest.cc
+++ b/chrome/browser/extensions/app_process_apitest.cc
@@ -5,7 +5,8 @@
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/extensions/extension_host.h"
-#include "chrome/browser/extensions/extension_process_manager.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
@@ -84,8 +85,8 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, AppProcess) {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kDisablePopupBlocking);
 
-  ExtensionProcessManager* extension_process_manager =
-      browser()->profile()->GetExtensionProcessManager();
+  extensions::ProcessMap* process_map =
+      browser()->profile()->GetExtensionService()->process_map();
 
   host_resolver()->AddRule("*", "127.0.0.1");
   ASSERT_TRUE(test_server()->Start());
@@ -103,7 +104,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, AppProcess) {
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("path1/empty.html"), NEW_FOREGROUND_TAB,
       ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       browser()->GetTabContentsAt(1)->render_view_host()->process()->id()));
   EXPECT_FALSE(browser()->GetTabContentsAt(1)->web_ui());
   LOG(INFO) << "Nav 1.";
@@ -111,7 +112,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, AppProcess) {
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("path2/empty.html"), NEW_FOREGROUND_TAB,
       ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       browser()->GetTabContentsAt(2)->render_view_host()->process()->id()));
   EXPECT_FALSE(browser()->GetTabContentsAt(2)->web_ui());
   LOG(INFO) << "Nav 2.";
@@ -124,7 +125,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, AppProcess) {
   LOG(INFO) << "New tab.";
   ui_test_utils::NavigateToURL(browser(), base_url.Resolve("path3/empty.html"));
   LOG(INFO) << "Nav 3.";
-  EXPECT_FALSE(extension_process_manager->IsExtensionProcess(
+  EXPECT_FALSE(process_map->Contains(
       browser()->GetTabContentsAt(3)->render_view_host()->process()->id()));
   EXPECT_FALSE(browser()->GetTabContentsAt(3)->web_ui());
 
@@ -196,8 +197,8 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, AppProcessInstances) {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kDisablePopupBlocking);
 
-  ExtensionProcessManager* extension_process_manager =
-      browser()->profile()->GetExtensionProcessManager();
+  extensions::ProcessMap* process_map =
+      browser()->profile()->GetExtensionService()->process_map();
 
   host_resolver()->AddRule("*", "127.0.0.1");
   ASSERT_TRUE(test_server()->Start());
@@ -215,7 +216,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, AppProcessInstances) {
       browser(), base_url.Resolve("path1/empty.html"), NEW_FOREGROUND_TAB,
       ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
   LOG(INFO) << "Nav 1.";
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       browser()->GetTabContentsAt(1)->render_view_host()->process()->id()));
   EXPECT_FALSE(browser()->GetTabContentsAt(1)->web_ui());
 
@@ -227,7 +228,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, AppProcessInstances) {
   LOG(INFO) << "New tab.";
   ui_test_utils::NavigateToURL(browser(), base_url.Resolve("path2/empty.html"));
   LOG(INFO) << "Nav 2.";
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       browser()->GetTabContentsAt(2)->render_view_host()->process()->id()));
   EXPECT_FALSE(browser()->GetTabContentsAt(2)->web_ui());
 
@@ -293,8 +294,8 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, DISABLED_ReloadIntoAppProcess) {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kDisablePopupBlocking);
 
-  ExtensionProcessManager* extension_process_manager =
-      browser()->profile()->GetExtensionProcessManager();
+  extensions::ProcessMap* process_map =
+      browser()->profile()->GetExtensionService()->process_map();
 
   host_resolver()->AddRule("*", "127.0.0.1");
   ASSERT_TRUE(test_server()->Start());
@@ -306,7 +307,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, DISABLED_ReloadIntoAppProcess) {
   // Load an app URL before loading the app.
   ui_test_utils::NavigateToURL(browser(), base_url.Resolve("path1/empty.html"));
   TabContents* contents = browser()->GetTabContentsAt(0);
-  EXPECT_FALSE(extension_process_manager->IsExtensionProcess(
+  EXPECT_FALSE(process_map->Contains(
       contents->render_view_host()->process()->id()));
 
   // Load app and navigate to the page.
@@ -314,13 +315,13 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, DISABLED_ReloadIntoAppProcess) {
       LoadExtension(test_data_dir_.AppendASCII("app_process"));
   ASSERT_TRUE(app);
   ui_test_utils::NavigateToURL(browser(), base_url.Resolve("path1/empty.html"));
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       contents->render_view_host()->process()->id()));
 
   // Disable app and navigate to the page.
   DisableExtension(app->id());
   ui_test_utils::NavigateToURL(browser(), base_url.Resolve("path1/empty.html"));
-  EXPECT_FALSE(extension_process_manager->IsExtensionProcess(
+  EXPECT_FALSE(process_map->Contains(
       contents->render_view_host()->process()->id()));
 
   // Enable app and reload the page.
@@ -331,7 +332,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, DISABLED_ReloadIntoAppProcess) {
           &browser()->GetSelectedTabContentsWrapper()->controller()));
   browser()->Reload(CURRENT_TAB);
   reload_observer.Wait();
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       contents->render_view_host()->process()->id()));
 
   // Disable app and reload the page.
@@ -342,7 +343,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, DISABLED_ReloadIntoAppProcess) {
           &browser()->GetSelectedTabContentsWrapper()->controller()));
   browser()->Reload(CURRENT_TAB);
   reload_observer2.Wait();
-  EXPECT_FALSE(extension_process_manager->IsExtensionProcess(
+  EXPECT_FALSE(process_map->Contains(
       contents->render_view_host()->process()->id()));
 
   // Enable app and reload via JavaScript.
@@ -354,7 +355,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, DISABLED_ReloadIntoAppProcess) {
   ASSERT_TRUE(ui_test_utils::ExecuteJavaScript(contents->render_view_host(),
                                                L"", L"location.reload();"));
   js_reload_observer.Wait();
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       contents->render_view_host()->process()->id()));
 
   // Disable app and reload via JavaScript.
@@ -366,7 +367,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, DISABLED_ReloadIntoAppProcess) {
   ASSERT_TRUE(ui_test_utils::ExecuteJavaScript(contents->render_view_host(),
                                                L"", L"location.reload();"));
   js_reload_observer2.Wait();
-  EXPECT_FALSE(extension_process_manager->IsExtensionProcess(
+  EXPECT_FALSE(process_map->Contains(
       contents->render_view_host()->process()->id()));
 }
 
@@ -379,8 +380,8 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, OpenAppFromIframe) {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kDisablePopupBlocking);
 
-  ExtensionProcessManager* extension_process_manager =
-      browser()->profile()->GetExtensionProcessManager();
+  extensions::ProcessMap* process_map =
+      browser()->profile()->GetExtensionService()->process_map();
 
   host_resolver()->AddRule("*", "127.0.0.1");
   ASSERT_TRUE(test_server()->Start());
@@ -397,7 +398,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, OpenAppFromIframe) {
       CURRENT_TAB,
       ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION |
           ui_test_utils::BROWSER_TEST_WAIT_FOR_BROWSER);
-  EXPECT_FALSE(extension_process_manager->IsExtensionProcess(
+  EXPECT_FALSE(process_map->Contains(
       browser()->GetTabContentsAt(0)->render_view_host()->process()->id()));
 
   // Wait for popup window to appear.
@@ -419,7 +420,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, OpenAppFromIframe) {
   }
 
   // Popup window should be in the app's process.
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       last_active_browser->GetTabContentsAt(0)->render_view_host()->process()->
           id()));
 }
@@ -435,8 +436,8 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, OpenWebPopupFromWebIframe) {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kDisablePopupBlocking);
 
-  ExtensionProcessManager* extension_process_manager =
-      browser()->profile()->GetExtensionProcessManager();
+  extensions::ProcessMap* process_map =
+      browser()->profile()->GetExtensionService()->process_map();
 
   host_resolver()->AddRule("*", "127.0.0.1");
   ASSERT_TRUE(test_server()->Start());
@@ -458,8 +459,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, OpenWebPopupFromWebIframe) {
           ui_test_utils::BROWSER_TEST_WAIT_FOR_BROWSER);
   RenderProcessHost* process =
       browser()->GetTabContentsAt(0)->render_view_host()->process();
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
-      process->id()));
+  EXPECT_TRUE(process_map->Contains(process->id()));
 
   // Wait for popup window to appear.  The new Browser may not have been
   // added with SetLastActive, in which case we need to show it first.
@@ -485,8 +485,9 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, OpenWebPopupFromWebIframe) {
 }
 
 IN_PROC_BROWSER_TEST_F(AppApiTest, ReloadAppAfterCrash) {
-  ExtensionProcessManager* extension_process_manager =
-      browser()->profile()->GetExtensionProcessManager();
+  extensions::ProcessMap* process_map =
+      browser()->profile()->GetExtensionService()->process_map();
+
   host_resolver()->AddRule("*", "127.0.0.1");
   ASSERT_TRUE(test_server()->Start());
 
@@ -497,7 +498,7 @@ IN_PROC_BROWSER_TEST_F(AppApiTest, ReloadAppAfterCrash) {
   // Load the app, chrome.app.isInstalled should be true.
   ui_test_utils::NavigateToURL(browser(), base_url.Resolve("path1/empty.html"));
   TabContents* contents = browser()->GetTabContentsAt(0);
-  EXPECT_TRUE(extension_process_manager->IsExtensionProcess(
+  EXPECT_TRUE(process_map->Contains(
       contents->render_view_host()->process()->id()));
   bool is_installed = false;
   ASSERT_TRUE(ui_test_utils::ExecuteJavaScriptAndExtractBool(
diff --git a/chrome/browser/extensions/extension_crash_recovery_browsertest.cc b/chrome/browser/extensions/extension_crash_recovery_browsertest.cc
index ee1bec2..98f63f5 100644
--- a/chrome/browser/extensions/extension_crash_recovery_browsertest.cc
+++ b/chrome/browser/extensions/extension_crash_recovery_browsertest.cc
@@ -90,8 +90,10 @@ class ExtensionCrashRecoveryTest : public ExtensionBrowserTest {
     ASSERT_TRUE(extension_host);
     ASSERT_TRUE(GetExtensionProcessManager()->HasExtensionHost(extension_host));
     ASSERT_TRUE(extension_host->IsRenderViewLive());
-    ASSERT_EQ(extension_host->render_view_host()->process(),
-        GetExtensionProcessManager()->GetExtensionProcess(extension->id()));
+    extensions::ProcessMap* process_map =
+        browser()->profile()->GetExtensionService()->process_map();
+    ASSERT_TRUE(process_map->Contains(
+        extension->id(), extension_host->render_view_host()->process()->id()));
   }
 
   void LoadTestExtension() {
diff --git a/chrome/browser/extensions/extension_event_router.cc b/chrome/browser/extensions/extension_event_router.cc
index 963477f..01b7c1b 100644
--- a/chrome/browser/extensions/extension_event_router.cc
+++ b/chrome/browser/extensions/extension_event_router.cc
@@ -15,6 +15,7 @@
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_tabs_module.h"
 #include "chrome/browser/extensions/extension_webrequest_api.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
@@ -29,7 +30,7 @@ namespace {
 
 const char kDispatchEvent[] = "Event.dispatchJSON";
 
-static void NotifyEventListenerRemovedOnIOThread(
+void NotifyEventListenerRemovedOnIOThread(
     void* profile,
     const std::string& extension_id,
     const std::string& sub_event_name) {
@@ -257,16 +258,6 @@ void ExtensionEventRouter::DispatchEventImpl(
   // Send the event only to renderers that are listening for it.
   for (std::set<EventListener>::iterator listener = listeners.begin();
        listener != listeners.end(); ++listener) {
-    Profile* listener_profile = Profile::FromBrowserContext(
-        listener->process->browser_context());
-    ExtensionProcessManager* extension_process_manager =
-        listener_profile->GetExtensionProcessManager();
-    if (!extension_process_manager->AreBindingsEnabledForProcess(
-        listener->process->id())) {
-      // Don't send browser-level events to unprivileged processes.
-      continue;
-    }
-
     if (!event->extension_id.empty() &&
         event->extension_id != listener->extension_id)
       continue;
@@ -279,6 +270,13 @@ void ExtensionEventRouter::DispatchEventImpl(
     if (!extension)
       continue;
 
+    Profile* listener_profile = Profile::FromBrowserContext(
+        listener->process->browser_context());
+    extensions::ProcessMap* process_map =
+        listener_profile->GetExtensionService()->process_map();
+    if (!process_map->Contains(extension->id(), listener->process->id()))
+      continue;
+
     // Is this event from a different profile than the renderer (ie, an
     // incognito tab event sent to a normal process, or vice versa).
     bool cross_incognito = event->restrict_to_profile &&
diff --git a/chrome/browser/extensions/extension_file_browser_private_api.cc b/chrome/browser/extensions/extension_file_browser_private_api.cc
index f0af322..ee540d0 100644
--- a/chrome/browser/extensions/extension_file_browser_private_api.cc
+++ b/chrome/browser/extensions/extension_file_browser_private_api.cc
@@ -21,6 +21,7 @@
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/extensions/file_manager_util.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/profiles/profile.h"
@@ -633,12 +634,17 @@ class ExecuteTasksFileSystemCallbackDispatcher
       const std::string task_id,
       const std::vector<GURL>& file_urls)
       : function_(function),
+        process_id_(0),
         profile_(profile),
         source_url_(source_url),
         extension_(extension),
         task_id_(task_id),
         origin_file_urls_(file_urls) {
     DCHECK(function_);
+    if (function_->render_view_host() &&
+        function_->render_view_host()->process()) {
+      process_id_ = function_->render_view_host()->process()->id();
+    }
   }
 
   // fileapi::FileSystemCallbackDispatcher overrides.
@@ -708,10 +714,13 @@ class ExecuteTasksFileSystemCallbackDispatcher
   // Checks legitimacy of file url and grants file RO access permissions from
   // handler (target) extension and its renderer process.
   bool SetupFileAccessPermissions(const GURL& origin_file_url,
-     GURL* target_file_url, FilePath* file_path, bool* is_directory) {
+    GURL* target_file_url, FilePath* file_path, bool* is_directory) {
     if (!extension_.get())
       return false;
 
+    if (process_id_ == 0)
+      return false;
+
     GURL file_origin_url;
     FilePath virtual_path;
     fileapi::FileSystemType type;
@@ -776,19 +785,13 @@ class ExecuteTasksFileSystemCallbackDispatcher
     // TODO(zelidrag): Add explicit R/W + R/O permissions for non-component
     // extensions.
 
-    // Get target extension's process.
-    RenderProcessHost* target_host =
-        profile_->GetExtensionProcessManager()->GetExtensionProcess(
-            target_extension_id);
-    if (!target_host)
-      return false;
-
     // Grant R/O access permission to non-component extension and R/W to
     // component extensions.
     ChildProcessSecurityPolicy::GetInstance()->GrantPermissionsForFile(
-        target_host->id(), final_file_path,
+        process_id_,
+        final_file_path,
         extension_->location() != Extension::COMPONENT ?
-            kReadOnlyFilePermissions : kReadWriteFilePermissions);
+        kReadOnlyFilePermissions : kReadWriteFilePermissions);
 
     // Grant access to this particular file to target extension. This will
     // ensure that the target extension can access only this FS entry and
@@ -809,6 +812,7 @@ class ExecuteTasksFileSystemCallbackDispatcher
   }
 
   ExecuteTasksFileBrowserFunction* function_;
+  int process_id_;
   Profile* profile_;
   // Extension source URL.
   GURL source_url_;
diff --git a/chrome/browser/extensions/extension_function_dispatcher.cc b/chrome/browser/extensions/extension_function_dispatcher.cc
index 068ae7a..4d0c94b 100644
--- a/chrome/browser/extensions/extension_function_dispatcher.cc
+++ b/chrome/browser/extensions/extension_function_dispatcher.cc
@@ -527,17 +527,10 @@ void ExtensionFunctionDispatcher::DispatchOnIOThread(
   const Extension* extension =
       extension_info_map->extensions().GetByURL(params.source_url);
 
-  if (!extension_info_map->IsExtensionInProcess(extension->id(),
-                                                render_process_id)) {
-    // TODO(aa): Allow content scripts access to low-threat extension APIs.
-    // See: crbug.com/80308.
-    LOG(ERROR) << "Extension API called from non-extension process.";
-    SendAccessDenied(ipc_sender, routing_id, params.request_id);
-    return;
-  }
-
-  scoped_refptr<ExtensionFunction> function(CreateExtensionFunction(
-      params, extension, profile, ipc_sender, routing_id));
+  scoped_refptr<ExtensionFunction> function(
+      CreateExtensionFunction(params, extension, render_process_id,
+                              extension_info_map->process_map(), profile,
+                              ipc_sender, routing_id));
   if (!function)
     return;
 
@@ -600,27 +593,9 @@ void ExtensionFunctionDispatcher::Dispatch(
     const ExtensionHostMsg_Request_Params& params,
     RenderViewHost* render_view_host) {
   ExtensionService* service = profile()->GetExtensionService();
-  ExtensionProcessManager* extension_process_manager =
-      profile()->GetExtensionProcessManager();
-  if (!service || !extension_process_manager)
-    return;
-
-  if (!service->ExtensionBindingsAllowed(params.source_url)) {
-    LOG(ERROR) << "Extension bindings not allowed for URL: "
-               << params.source_url.spec();
-    SendAccessDenied(render_view_host, render_view_host->routing_id(),
-                     params.request_id);
+  extensions::ProcessMap* process_map = service->process_map();
+  if (!service || !process_map)
     return;
-  }
-  if (!extension_process_manager->AreBindingsEnabledForProcess(
-      render_view_host->process()->id())) {
-    // TODO(aa): Allow content scripts access to low-threat extension APIs.
-    // See: crbug.com/80308.
-    LOG(ERROR) << "Extension API called from non-extension process.";
-    SendAccessDenied(render_view_host, render_view_host->routing_id(),
-                     params.request_id);
-    return;
-  }
 
   // TODO(aa): When we allow content scripts to call extension APIs, we will
   // have to pass the extension ID explicitly here, not use the source URL.
@@ -629,7 +604,10 @@ void ExtensionFunctionDispatcher::Dispatch(
     extension = service->GetExtensionByWebExtent(params.source_url);
 
   scoped_refptr<ExtensionFunction> function(
-      CreateExtensionFunction(params, extension, profile(), render_view_host,
+      CreateExtensionFunction(params, extension,
+                              render_view_host->process()->id(),
+                              *(service->process_map()),
+                              profile(), render_view_host,
                               render_view_host->routing_id()));
   if (!function)
     return;
@@ -661,12 +639,21 @@ void ExtensionFunctionDispatcher::Dispatch(
 ExtensionFunction* ExtensionFunctionDispatcher::CreateExtensionFunction(
     const ExtensionHostMsg_Request_Params& params,
     const Extension* extension,
+    int requesting_process_id,
+    const extensions::ProcessMap& process_map,
     void* profile,
     IPC::Message::Sender* ipc_sender,
     int routing_id) {
   if (!extension) {
-    LOG(ERROR) << "Extension does not exist for URL: "
-               << params.source_url.spec();
+    LOG(ERROR) << "Specified extension does not exist.";
+    SendAccessDenied(ipc_sender, routing_id, params.request_id);
+    return NULL;
+  }
+
+  if (!process_map.Contains(extension->id(), requesting_process_id)) {
+    LOG(ERROR) << "Extension API called from incorrect process "
+               << requesting_process_id
+               << " from URL " << params.source_url.spec();
     SendAccessDenied(ipc_sender, routing_id, params.request_id);
     return NULL;
   }
diff --git a/chrome/browser/extensions/extension_function_dispatcher.h b/chrome/browser/extensions/extension_function_dispatcher.h
index a45efc4c..fd4c7da 100644
--- a/chrome/browser/extensions/extension_function_dispatcher.h
+++ b/chrome/browser/extensions/extension_function_dispatcher.h
@@ -24,6 +24,10 @@ class RenderViewHost;
 class TabContents;
 struct ExtensionHostMsg_Request_Params;
 
+namespace extensions {
+class ProcessMap;
+}
+
 // A factory function for creating new ExtensionFunction instances.
 typedef ExtensionFunction* (*ExtensionFunctionFactory)();
 
@@ -117,6 +121,8 @@ class ExtensionFunctionDispatcher
   static ExtensionFunction* CreateExtensionFunction(
       const ExtensionHostMsg_Request_Params& params,
       const Extension* extension,
+      int requesting_process_id,
+      const extensions::ProcessMap& process_map,
       void* profile,
       IPC::Message::Sender* ipc_sender,
       int routing_id);
diff --git a/chrome/browser/extensions/extension_info_map.cc b/chrome/browser/extensions/extension_info_map.cc
index ed3fd7d..01ee98b 100644
--- a/chrome/browser/extensions/extension_info_map.cc
+++ b/chrome/browser/extensions/extension_info_map.cc
@@ -44,6 +44,10 @@ ExtensionInfoMap::ExtensionInfoMap() {
 ExtensionInfoMap::~ExtensionInfoMap() {
 }
 
+const extensions::ProcessMap& ExtensionInfoMap::process_map() const {
+  return process_map_;
+}
+
 void ExtensionInfoMap::AddExtension(const Extension* extension,
                                     base::Time install_time,
                                     bool incognito_enabled) {
@@ -102,29 +106,23 @@ bool ExtensionInfoMap::CanCrossIncognito(const Extension* extension) {
 
 void ExtensionInfoMap::RegisterExtensionProcess(const std::string& extension_id,
                                                 int process_id) {
-  DCHECK(!IsExtensionInProcess(extension_id, process_id));
-  extension_process_ids_.insert(
-      ExtensionProcessIDMap::value_type(extension_id, process_id));
+  if (!process_map_.Insert(extension_id, process_id)) {
+    NOTREACHED() << "Duplicate extension process registration for: "
+                 << extension_id << "," << process_id << ".";
+  }
 }
 
 void ExtensionInfoMap::UnregisterExtensionProcess(
     const std::string& extension_id,
     int process_id) {
-  ExtensionProcessIDMap::iterator iter =
-      std::find(extension_process_ids_.begin(),
-                extension_process_ids_.end(),
-                ExtensionProcessIDMap::value_type(extension_id, process_id));
-  if (iter != extension_process_ids_.end())
-    extension_process_ids_.erase(iter);
+  if (!process_map_.Remove(extension_id, process_id)) {
+    NOTREACHED() << "Unknown extension process registration for: "
+                 << extension_id << "," << process_id << ".";
+  }
 }
 
-bool ExtensionInfoMap::IsExtensionInProcess(
-    const std::string& extension_id, int process_id) const {
-  return std::find(
-      extension_process_ids_.begin(),
-      extension_process_ids_.end(),
-      ExtensionProcessIDMap::value_type(extension_id, process_id)) !=
-          extension_process_ids_.end();
+void ExtensionInfoMap::UnregisterAllExtensionsInProcess(int process_id) {
+  process_map_.Remove(process_id);
 }
 
 bool ExtensionInfoMap::SecurityOriginHasAPIPermission(
@@ -133,13 +131,13 @@ bool ExtensionInfoMap::SecurityOriginHasAPIPermission(
   if (origin.SchemeIs(chrome::kExtensionScheme)) {
     const std::string& id = origin.host();
     return extensions_.GetByID(id)->HasAPIPermission(permission) &&
-           IsExtensionInProcess(id, process_id);
+        process_map_.Contains(id, process_id);
   }
 
   ExtensionSet::ExtensionMap::const_iterator i = extensions_.begin();
   for (; i != extensions_.end(); ++i) {
     if (i->second->web_extent().MatchesSecurityOrigin(origin) &&
-        IsExtensionInProcess(i->first, process_id) &&
+        process_map_.Contains(i->first, process_id) &&
         i->second->HasAPIPermission(permission)) {
       return true;
     }
diff --git a/chrome/browser/extensions/extension_info_map.h b/chrome/browser/extensions/extension_info_map.h
index 6aaf6b0..e8f1afa 100644
--- a/chrome/browser/extensions/extension_info_map.h
+++ b/chrome/browser/extensions/extension_info_map.h
@@ -6,13 +6,13 @@
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_INFO_MAP_H_
 #pragma once
 
-#include <map>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/time.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/extensions/extensions_quota_service.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/extensions/extension_set.h"
 
@@ -31,6 +31,8 @@ class ExtensionInfoMap : public base::RefCountedThreadSafe<ExtensionInfoMap> {
     return disabled_extensions_;
   }
 
+  const extensions::ProcessMap& process_map() const;
+
   // Callback for when new extensions are loaded.
   void AddExtension(const Extension* extension,
                     base::Time install_time,
@@ -51,21 +53,14 @@ class ExtensionInfoMap : public base::RefCountedThreadSafe<ExtensionInfoMap> {
   // sub-profile (incognito to original profile, or vice versa).
   bool CanCrossIncognito(const Extension* extension);
 
-  // Record that |extension_id| is running in |process_id|. We normally have
-  // this information in  ExtensionProcessManager on the UI thread, but we also
-  // sometimes need it on the IO thread. Note that this can be any of
-  // (extension, packaged app, hosted app).
+  // Adds an entry to process_map_.
   void RegisterExtensionProcess(const std::string& extension_id,
                                 int process_id);
 
-  // Remove any record of |extension_id| created with RegisterExtensionProcess.
-  // If |extension_id| is unknown, we ignore it.
+  // Removes an entry from process_map_.
   void UnregisterExtensionProcess(const std::string& extension_id,
                                   int process_id);
-
-  // Returns true if |extension_id| is running in |process_id|..
-  bool IsExtensionInProcess(const std::string& extension_id,
-                            int process_id) const;
+  void UnregisterAllExtensionsInProcess(int process_id);
 
   // Returns true if there is exists an extension with the same origin as
   // |origin| in |process_id| with |permission|.
@@ -87,11 +82,11 @@ class ExtensionInfoMap : public base::RefCountedThreadSafe<ExtensionInfoMap> {
   // Extra data associated with enabled extensions.
   ExtraDataMap extra_data_;
 
-  typedef std::multimap<std::string, int> ExtensionProcessIDMap;
-  ExtensionProcessIDMap extension_process_ids_;
-
   // Used by dispatchers to limit API quota for individual extensions.
   ExtensionsQuotaService quota_service_;
+
+  // Assignment of extensions to processes.
+  extensions::ProcessMap process_map_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_INFO_MAP_H_
diff --git a/chrome/browser/extensions/extension_message_service.cc b/chrome/browser/extensions/extension_message_service.cc
index f1febd7..d89b6e6 100644
--- a/chrome/browser/extensions/extension_message_service.cc
+++ b/chrome/browser/extensions/extension_message_service.cc
@@ -10,6 +10,7 @@
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_process_manager.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
@@ -93,6 +94,18 @@ static void DispatchOnMessage(const ExtensionMessageService::MessagePort& port,
           port.routing_id, target_port_id, message));
 }
 
+static RenderProcessHost* GetExtensionProcess(Profile* profile,
+                                              const std::string& extension_id) {
+  SiteInstance* site_instance =
+      profile->GetExtensionProcessManager()->GetSiteInstanceForURL(
+          Extension::GetBaseURLFromExtensionId(extension_id));
+
+  if (!site_instance->HasProcess())
+    return NULL;
+
+  return site_instance->GetProcess();
+}
+
 }  // namespace
 
 // static
@@ -149,8 +162,7 @@ void ExtensionMessageService::OpenChannelToExtension(
   // process, we will use the incognito EPM to find the right extension process,
   // which depends on whether the extension uses spanning or split mode.
   MessagePort receiver(
-      profile->GetExtensionProcessManager()->GetExtensionProcess(
-          target_extension_id),
+      GetExtensionProcess(profile, target_extension_id),
       MSG_ROUTING_CONTROL);
   TabContents* source_contents = tab_util::GetTabContentsByID(
       source_process_id, source_routing_id);
@@ -258,7 +270,7 @@ int ExtensionMessageService::OpenSpecialChannelToExtension(
   AllocatePortIdPair(&port1_id, &port2_id);
 
   MessagePort receiver(
-      profile_->GetExtensionProcessManager()->GetExtensionProcess(extension_id),
+      GetExtensionProcess(profile_, extension_id),
       MSG_ROUTING_CONTROL);
   if (!OpenChannelImpl(source, tab_json, receiver, port2_id,
                        extension_id, extension_id, channel_name))
diff --git a/chrome/browser/extensions/extension_process_manager.cc b/chrome/browser/extensions/extension_process_manager.cc
index cf9b70b..2fa8461 100644
--- a/chrome/browser/extensions/extension_process_manager.cc
+++ b/chrome/browser/extensions/extension_process_manager.cc
@@ -47,8 +47,6 @@ class IncognitoExtensionProcessManager : public ExtensionProcessManager {
   virtual void CreateBackgroundHost(const Extension* extension,
                                     const GURL& url);
   virtual SiteInstance* GetSiteInstanceForURL(const GURL& url);
-  virtual RenderProcessHost* GetExtensionProcess(const GURL& url);
-  virtual const Extension* GetExtensionForSiteInstance(int site_instance_id);
 
  private:
   // content::NotificationObserver:
@@ -109,10 +107,6 @@ ExtensionProcessManager::ExtensionProcessManager(Profile* profile)
                  content::Source<Profile>(profile));
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_HOST_VIEW_SHOULD_CLOSE,
                  content::Source<Profile>(profile));
-  // We can listen to everything for SITE_INSTANCE_DELETED because we check the
-  // |site_instance_id| in UnregisterExtensionSiteInstance.
-  registrar_.Add(this, content::NOTIFICATION_SITE_INSTANCE_DELETED,
-                 content::NotificationService::AllBrowserContextsAndSources());
   registrar_.Add(this, content::NOTIFICATION_APP_TERMINATING,
                  content::NotificationService::AllSources());
 }
@@ -265,7 +259,6 @@ void ExtensionProcessManager::RegisterRenderViewHost(
     RenderViewHost* render_view_host,
     const Extension* extension) {
   all_extension_views_.insert(render_view_host);
-  RegisterExtensionSiteInstance(render_view_host->site_instance(), extension);
 }
 
 void ExtensionProcessManager::UnregisterRenderViewHost(
@@ -273,155 +266,6 @@ void ExtensionProcessManager::UnregisterRenderViewHost(
   all_extension_views_.erase(render_view_host);
 }
 
-void ExtensionProcessManager::RegisterExtensionSiteInstance(
-    SiteInstance* site_instance,
-    const Extension* extension) {
-  if (!site_instance->HasProcess()) {
-    NOTREACHED();
-    return;
-  }
-
-  int site_instance_id = site_instance->id();
-  int render_process_id = site_instance->GetProcess()->id();
-  if (process_ids_[render_process_id].insert(site_instance_id).second) {
-    // Register process hosting extensions that have access to extension
-    // bindings with the ExtensionInfoMap on the IO thread.
-    Profile* profile =
-        Profile::FromBrowserContext(browsing_instance_->browser_context());
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&ExtensionInfoMap::RegisterExtensionProcess,
-                   profile->GetExtensionInfoMap(),
-                   extension->id(),
-                   render_process_id));
-  }
-
-  SiteInstanceIDMap::const_iterator it = extension_ids_.find(site_instance_id);
-  if (it != extension_ids_.end() && (*it).second == extension->id())
-    return;
-
-  // SiteInstance ids should get removed from the map before the extension ids
-  // get used for a new SiteInstance.
-  DCHECK(it == extension_ids_.end());
-  extension_ids_[site_instance_id] = extension->id();
-}
-
-void ExtensionProcessManager::UnregisterExtensionSiteInstance(
-    SiteInstance* site_instance) {
-  int site_instance_id = site_instance->id();
-  std::string extension_id = extension_ids_[site_instance_id];
-  if (!extension_id.empty())
-    extension_ids_.erase(site_instance_id);
-
-  int render_process_id = ClearSiteInstanceID(site_instance_id);
-  if (render_process_id == -1)
-    return;
-
-  Profile* profile = Profile::FromBrowserContext(
-      browsing_instance_->browser_context());
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&ExtensionInfoMap::UnregisterExtensionProcess,
-                 profile->GetExtensionInfoMap(),
-                 extension_id,
-                 render_process_id));
-}
-
-int ExtensionProcessManager::ClearSiteInstanceID(int site_instance_id) {
-  for (ProcessIDMap::iterator i = process_ids_.begin();
-       i != process_ids_.end(); ++i) {
-    SiteInstanceIDSet& site_instance_id_set = i->second;
-    for (SiteInstanceIDSet::iterator j = site_instance_id_set.begin();
-         j != site_instance_id_set.end(); ++j) {
-      if (*j == site_instance_id) {
-        int render_process_id = i->first;
-        site_instance_id_set.erase(j);
-        if (site_instance_id_set.empty())
-          process_ids_.erase(i);
-        return render_process_id;
-      }
-    }
-  }
-  return -1;
-}
-
-bool ExtensionProcessManager::IsExtensionProcess(int render_process_id) {
-  return process_ids_.find(render_process_id) != process_ids_.end();
-}
-
-bool ExtensionProcessManager::AreBindingsEnabledForProcess(
-    int render_process_id) {
-  // Must behave logically the same as AreBindingsEnabledForProcess() in
-  // extension_info_map.cc.
-  ProcessIDMap::iterator it = process_ids_.find(render_process_id);
-  if (it == process_ids_.end())
-    return false;
-
-  Profile* profile =
-      Profile::FromBrowserContext(browsing_instance_->browser_context());
-  ExtensionService* service = profile->GetExtensionService();
-  for (std::set<int>::iterator site_instance_id = it->second.begin();
-       site_instance_id != it->second.end(); ++site_instance_id) {
-    const Extension* extension =
-        GetExtensionForSiteInstance(*site_instance_id);
-    if (extension == NULL)
-      continue;
-    if (service->ExtensionBindingsAllowed(extension->url()))
-      return true;
-  }
-  return false;
-}
-
-RenderProcessHost* ExtensionProcessManager::GetExtensionProcess(
-    const GURL& url) {
-  if (!browsing_instance_->HasSiteInstance(url))
-    return NULL;
-  scoped_refptr<SiteInstance> site(
-      browsing_instance_->GetSiteInstanceForURL(url));
-  if (site->HasProcess())
-    return site->GetProcess();
-  return NULL;
-}
-
-RenderProcessHost* ExtensionProcessManager::GetExtensionProcess(
-    const std::string& extension_id) {
-  return GetExtensionProcess(
-      Extension::GetBaseURLFromExtensionId(extension_id));
-}
-
-const Extension* ExtensionProcessManager::GetExtensionForSiteInstance(
-    int site_instance_id) {
-  SiteInstanceIDMap::const_iterator it = extension_ids_.find(site_instance_id);
-  if (it != extension_ids_.end()) {
-    // Look up the extension by ID, including disabled extensions in case
-    // this gets called while an old process is still around.
-    Profile* profile =
-        Profile::FromBrowserContext(browsing_instance_->browser_context());
-    ExtensionService* service = profile->GetExtensionService();
-    return service->GetExtensionById(it->second, false);
-  }
-
-  return NULL;
-}
-
-std::set<const Extension*> ExtensionProcessManager::GetExtensionsForProcess(
-    int process_id) {
-  std::set<const Extension*> result;
-
-  ProcessIDMap::iterator site_id_set = process_ids_.find(process_id);
-  if (site_id_set == process_ids_.end())
-    return result;
-
-  for (std::set<int>::iterator site_id = site_id_set->second.begin();
-       site_id != site_id_set->second.end(); ++site_id) {
-    const Extension* extension = GetExtensionForSiteInstance(*site_id);
-    if (extension)
-      result.insert(extension);
-  }
-
-  return result;
-}
-
 SiteInstance* ExtensionProcessManager::GetSiteInstanceForURL(const GURL& url) {
   return browsing_instance_->GetSiteInstanceForURL(url);
 }
@@ -499,12 +343,6 @@ void ExtensionProcessManager::Observe(
       break;
     }
 
-    case content::NOTIFICATION_SITE_INSTANCE_DELETED: {
-      SiteInstance* site_instance = content::Source<SiteInstance>(source).ptr();
-      UnregisterExtensionSiteInstance(site_instance);
-      break;
-    }
-
     case chrome::NOTIFICATION_EXTENSION_HOST_VIEW_SHOULD_CLOSE: {
       ExtensionHost* host = content::Details<ExtensionHost>(details).ptr();
       if (host->extension_host_type() ==
@@ -609,27 +447,6 @@ SiteInstance* IncognitoExtensionProcessManager::GetSiteInstanceForURL(
   }
 }
 
-RenderProcessHost* IncognitoExtensionProcessManager::GetExtensionProcess(
-    const GURL& url) {
-  const Extension* extension = GetExtensionOrAppByURL(url);
-  if (!extension || extension->incognito_split_mode()) {
-    return ExtensionProcessManager::GetExtensionProcess(url);
-  } else {
-    return original_manager_->GetExtensionProcess(url);
-  }
-}
-
-const Extension* IncognitoExtensionProcessManager::GetExtensionForSiteInstance(
-    int site_instance_id) {
-  const Extension* extension =
-      ExtensionProcessManager::GetExtensionForSiteInstance(site_instance_id);
-  if (extension && extension->incognito_split_mode()) {
-    return extension;
-  } else {
-    return original_manager_->GetExtensionForSiteInstance(site_instance_id);
-  }
-}
-
 const Extension* IncognitoExtensionProcessManager::GetExtensionOrAppByURL(
     const GURL& url) {
   Profile* profile =
diff --git a/chrome/browser/extensions/extension_process_manager.h b/chrome/browser/extensions/extension_process_manager.h
index 476c053..3ee2a4f 100644
--- a/chrome/browser/extensions/extension_process_manager.h
+++ b/chrome/browser/extensions/extension_process_manager.h
@@ -68,6 +68,8 @@ class ExtensionProcessManager : public content::NotificationObserver {
   ExtensionHost* GetBackgroundHostForExtension(const std::string& extension_id);
 
   // Returns the SiteInstance that the given URL belongs to.
+  // TODO(aa): This only returns correct results for extensions and packaged
+  // apps, not hosted apps.
   virtual SiteInstance* GetSiteInstanceForURL(const GURL& url);
 
   // Registers a RenderViewHost as hosting a given extension.
@@ -82,28 +84,6 @@ class ExtensionProcessManager : public content::NotificationObserver {
   std::set<RenderViewHost*> GetRenderViewHostsForExtension(
       const std::string& extension_id);
 
-  // True if this process host is hosting an extension.
-  bool IsExtensionProcess(int render_process_id);
-
-  // True if this process host is hosting an extension with extension bindings
-  // enabled.
-  bool AreBindingsEnabledForProcess(int render_process_id);
-
-  // Returns the extension process that |url| is associated with if it exists.
-  // This is not valid for hosted apps without the background permission, since
-  // such apps may have multiple processes.
-  virtual RenderProcessHost* GetExtensionProcess(const GURL& url);
-
-  // Returns the process that the extension with the given ID is running in.
-  RenderProcessHost* GetExtensionProcess(const std::string& extension_id);
-
-  // Returns the Extension associated with the given SiteInstance id, if any.
-  virtual const Extension* GetExtensionForSiteInstance(int site_instance_id);
-
-  // Returns the set of extensions for the specified process. If the process is
-  // not an extension process, or contains no extensions, returns an empty set.
-  std::set<const Extension*> GetExtensionsForProcess(int process_id);
-
   // Returns true if |host| is managed by this process manager.
   bool HasExtensionHost(ExtensionHost* host) const;
 
@@ -142,23 +122,7 @@ class ExtensionProcessManager : public content::NotificationObserver {
   // controls process grouping.
   scoped_refptr<BrowsingInstance> browsing_instance_;
 
-  // A map of site instance ID to the ID of the extension it hosts.
-  typedef std::map<int, std::string> SiteInstanceIDMap;
-  SiteInstanceIDMap extension_ids_;
-
-  // A map of process ID to site instance ID of the site instances it hosts.
-  typedef std::set<int> SiteInstanceIDSet;
-  typedef std::map<int, SiteInstanceIDSet> ProcessIDMap;
-  ProcessIDMap process_ids_;
-
  private:
-  // Registers a site instance as hosting a given extension.
-  void RegisterExtensionSiteInstance(SiteInstance* site_instance,
-                                     const Extension* extension);
-
-  // Unregisters the extension associated with |site_instance|.
-  void UnregisterExtensionSiteInstance(SiteInstance* site_instance);
-
   // Contains all extension-related RenderViewHost instances for all extensions.
   typedef std::set<RenderViewHost*> RenderViewHostSet;
   RenderViewHostSet all_extension_views_;
@@ -169,10 +133,6 @@ class ExtensionProcessManager : public content::NotificationObserver {
   // Excludes background page.
   bool HasVisibleViews(const std::string& extension_id);
 
-  // Clears the mapping for the specified site instance. Returns the process the
-  // site was mapped to, or -1 if it wasn't found.
-  int ClearSiteInstanceID(int site_instance_id);
-
   DISALLOW_COPY_AND_ASSIGN(ExtensionProcessManager);
 };
 
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index b2d09b6..a42fe0f 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -2339,6 +2339,13 @@ void ExtensionService::Observe(int type,
           break;
 
       installed_app_hosts_.erase(process->id());
+
+      process_map_.Remove(process->id());
+      BrowserThread::PostTask(
+          BrowserThread::IO, FROM_HERE,
+          base::Bind(&ExtensionInfoMap::UnregisterAllExtensionsInProcess,
+                     profile_->GetExtensionInfoMap(),
+                     process->id()));
       break;
     }
     case chrome::NOTIFICATION_PREF_CHANGED: {
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index 47cc52d..60da15b 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -33,6 +33,7 @@
 #include "chrome/browser/extensions/extensions_quota_service.h"
 #include "chrome/browser/extensions/external_extension_provider_interface.h"
 #include "chrome/browser/extensions/pending_extension_manager.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/extensions/sandboxed_extension_unpacker.h"
 #include "chrome/browser/prefs/pref_change_registrar.h"
 #include "chrome/browser/sync/api/sync_change.h"
@@ -186,6 +187,8 @@ class ExtensionService
 
   AppsPromo* apps_promo() { return &apps_promo_; }
 
+  extensions::ProcessMap* process_map() { return &process_map_; }
+
   // Whether this extension can run in an incognito window.
   virtual bool IsIncognitoEnabled(const std::string& extension_id) const;
   virtual void SetIsIncognitoEnabled(const std::string& extension_id,
@@ -788,6 +791,8 @@ class ExtensionService
   // Contains an entry for each warning that shall be currently shown.
   ExtensionWarningSet extension_warnings_;
 
+  extensions::ProcessMap process_map_;
+
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsWithUnlimtedStorage);
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
diff --git a/chrome/browser/extensions/extension_tab_helper.cc b/chrome/browser/extensions/extension_tab_helper.cc
index d597396..7aa3ce5 100644
--- a/chrome/browser/extensions/extension_tab_helper.cc
+++ b/chrome/browser/extensions/extension_tab_helper.cc
@@ -168,19 +168,16 @@ void ExtensionTabHelper::OnGetAppNotifyChannel(
   Profile* profile =
       Profile::FromBrowserContext(tab_contents()->browser_context());
   ExtensionService* extension_service = profile->GetExtensionService();
-  ExtensionProcessManager* process_manager =
-      profile->GetExtensionProcessManager();
+  extensions::ProcessMap* process_map = extension_service->process_map();
   RenderProcessHost* process =
       tab_contents_wrapper()->render_view_host()->process();
   const Extension* extension =
       extension_service->GetInstalledApp(requestor_url);
   bool allowed =
       extension &&
-      extension->is_app() &&
       extension->HasAPIPermission(
           ExtensionAPIPermission::kExperimental) &&
-      (extension->is_hosted_app() ||
-       process_manager->GetExtensionProcess(requestor_url) == process);
+      process_map->Contains(extension->id(), process->id());
   if (!allowed) {
     AppNotifyChannelSetupComplete("", "permission_error", return_route_id,
                                   callback_id);
diff --git a/chrome/browser/extensions/process_map.cc b/chrome/browser/extensions/process_map.cc
new file mode 100644
index 0000000..fa12f6c
--- /dev/null
+++ b/chrome/browser/extensions/process_map.cc
@@ -0,0 +1,89 @@
+// 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 "chrome/browser/extensions/process_map.h"
+
+namespace extensions {
+
+// Item
+ProcessMap::Item::Item() {
+}
+
+ProcessMap::Item::Item(const ProcessMap::Item& other)
+    : extension_id(other.extension_id), process_id(other.process_id) {
+}
+
+ProcessMap::Item::Item(const std::string& extension_id, int process_id)
+    : extension_id(extension_id), process_id(process_id) {
+}
+
+ProcessMap::Item::~Item() {
+}
+
+bool ProcessMap::Item::operator<(const ProcessMap::Item& other) const {
+  if (extension_id < other.extension_id)
+    return true;
+
+  if (extension_id == other.extension_id &&
+      process_id < other.process_id) {
+    return true;
+  }
+
+  return false;
+}
+
+
+// ProcessMap
+ProcessMap::ProcessMap() {
+}
+
+ProcessMap::~ProcessMap() {
+}
+
+bool ProcessMap::Insert(const std::string& extension_id, int process_id) {
+  return items_.insert(Item(extension_id, process_id)).second;
+}
+
+bool ProcessMap::Remove(const std::string& extension_id, int process_id) {
+  return items_.erase(Item(extension_id, process_id)) > 0;
+}
+
+int ProcessMap::Remove(int process_id) {
+  int result = 0;
+  for (ItemSet::const_iterator iter = items_.begin(); iter != items_.end(); ) {
+    if (iter->process_id == process_id) {
+      items_.erase(iter++);
+      ++result;
+    } else {
+      ++iter;
+    }
+  }
+  return result;
+}
+
+bool ProcessMap::Contains(const std::string& extension_id,
+                          int process_id) const {
+  return items_.find(Item(extension_id, process_id)) != items_.end();
+}
+
+bool ProcessMap::Contains(int process_id) const {
+  for (ItemSet::const_iterator iter = items_.begin(); iter != items_.end();
+       ++iter) {
+    if (iter->process_id == process_id)
+      return true;
+  }
+  return false;
+}
+
+std::set<std::string> ProcessMap::GetExtensionsInProcess(int process_id) const {
+  std::set<std::string> result;
+  for (ItemSet::const_iterator iter = items_.begin(); iter != items_.end();
+       ++iter) {
+    if (iter->process_id == process_id)
+      result.insert(iter->extension_id);
+  }
+  return result;
+}
+
+}  // extensions
diff --git a/chrome/browser/extensions/process_map.h b/chrome/browser/extensions/process_map.h
new file mode 100644
index 0000000..9d43505
--- /dev/null
+++ b/chrome/browser/extensions/process_map.h
@@ -0,0 +1,73 @@
+// 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 CHROME_BROWSER_EXTENSIONS_PROCESS_MAP_H_
+#define CHROME_BROWSER_EXTENSIONS_PROCESS_MAP_H_
+#pragma once
+
+#include <set>
+#include <string>
+
+#include "base/basictypes.h"
+
+namespace extensions {
+
+// Contains information about which extensions are assigned to which processes.
+//
+// The relationship between extensions and processes is complex:
+// - Extensions can be either "split" mode or "spanning" mode.
+// - In spanning mode, extensions share a single process between all incognito
+//   and normal windows. This was the original mode for extensions.
+// - In split mode, extensions have separate processes in incognito windows.
+// - There are also hosted apps, which are a kind of extensions, and those
+//   usually have a process model similar to normal web sites: multiple
+//   processes per-profile.
+//
+// In general, we seem to play with the process model of extensions a lot, so
+// it is safest to assume it is many-to-many in most places in the codebase.
+//
+// Note that because of content scripts, frames, and other edge cases in
+// Chrome's process isolation, extension code can still end up running outside
+// an assigned process.
+//
+// But we only allow high-privilege operations to be performed by an extension
+// when it is running in an assigned process.
+class ProcessMap {
+ public:
+  ProcessMap();
+  ~ProcessMap();
+
+  size_t size() const { return items_.size(); }
+
+  bool Insert(const std::string& extension_id, int process_id);
+  bool Remove(const std::string& extension_id, int process_id);
+  int Remove(int process_id);
+  bool Contains(const std::string& extension_id, int process_id) const;
+  bool Contains(int process_id) const;
+
+  std::set<std::string> GetExtensionsInProcess(int process_id) const;
+
+ private:
+  struct Item {
+    Item();
+    Item(const Item& other);
+    Item(const std::string& extension_id, int process_id);
+    ~Item();
+
+    // Required for set membership.
+    bool operator<(const Item& other) const;
+
+    std::string extension_id;
+    int process_id;
+  };
+
+  typedef std::set<Item> ItemSet;
+  std::set<Item> items_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProcessMap);
+};
+
+}  // extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_PROCESS_MAP_H_
diff --git a/chrome/browser/extensions/process_map_unittest.cc b/chrome/browser/extensions/process_map_unittest.cc
new file mode 100644
index 0000000..40b3e595
--- /dev/null
+++ b/chrome/browser/extensions/process_map_unittest.cc
@@ -0,0 +1,52 @@
+// 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 "chrome/browser/extensions/process_map.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+using extensions::ProcessMap;
+
+TEST(ExtensionProcessMapTest, Test) {
+  ProcessMap map;
+
+  // Test behavior when empty.
+  EXPECT_FALSE(map.Contains("a", 1));
+  EXPECT_FALSE(map.Remove("a", 1));
+  EXPECT_EQ(0u, map.size());
+
+  // Test insertion and behavior with one item.
+  EXPECT_TRUE(map.Insert("a", 1));
+  EXPECT_TRUE(map.Contains("a", 1));
+  EXPECT_FALSE(map.Contains("a", 2));
+  EXPECT_FALSE(map.Contains("b", 1));
+  EXPECT_EQ(1u, map.size());
+
+  // Test inserting a duplicate item.
+  EXPECT_FALSE(map.Insert("a", 1));
+  EXPECT_TRUE(map.Contains("a", 1));
+  EXPECT_EQ(1u, map.size());
+
+  // Insert some more items.
+  EXPECT_TRUE(map.Insert("a", 2));
+  EXPECT_TRUE(map.Insert("b", 1));
+  EXPECT_TRUE(map.Insert("b", 2));
+  EXPECT_EQ(4u, map.size());
+
+  EXPECT_TRUE(map.Contains("a", 1));
+  EXPECT_TRUE(map.Contains("a", 2));
+  EXPECT_TRUE(map.Contains("b", 1));
+  EXPECT_TRUE(map.Contains("b", 2));
+  EXPECT_FALSE(map.Contains("a", 3));
+
+  // Test removal.
+  EXPECT_TRUE(map.Remove("a", 1));
+  EXPECT_FALSE(map.Remove("a", 1));
+  EXPECT_EQ(3u, map.size());
+
+  EXPECT_EQ(2, map.Remove(2));
+  EXPECT_EQ(1u, map.size());
+  EXPECT_EQ(0, map.Remove(2));
+  EXPECT_EQ(1u, map.size());
+}
diff --git a/chrome/browser/geolocation/chrome_geolocation_permission_context.cc b/chrome/browser/geolocation/chrome_geolocation_permission_context.cc
index b160c38..0328da9 100644
--- a/chrome/browser/geolocation/chrome_geolocation_permission_context.cc
+++ b/chrome/browser/geolocation/chrome_geolocation_permission_context.cc
@@ -530,18 +530,11 @@ void ChromeGeolocationPermissionContext::RequestGeolocationPermission(
     if (!ext)
       ext = extensions->GetExtensionByWebExtent(requesting_frame);
     if (ext && ext->HasAPIPermission(ExtensionAPIPermission::kGeolocation)) {
-      // Make sure this matches the current extension.
-      RenderViewHost* rvh = RenderViewHost::FromID(render_process_id,
-                                                   render_view_id);
-      if (rvh && rvh->site_instance()) {
-        ExtensionProcessManager* epm = profile_->GetExtensionProcessManager();
-        const Extension* current_ext = epm->GetExtensionForSiteInstance(
-            rvh->site_instance()->id());
-        if (ext == current_ext) {
-          NotifyPermissionSet(render_process_id, render_view_id, bridge_id,
-                              requesting_frame, true);
-          return;
-        }
+      // Make sure the extension is in the calling process.
+      if (extensions->process_map()->Contains(ext->id(), render_process_id)) {
+        NotifyPermissionSet(render_process_id, render_view_id, bridge_id,
+                            requesting_frame, true);
+        return;
       }
     }
   }
diff --git a/chrome/browser/memory_details.cc b/chrome/browser/memory_details.cc
index 138a51d..3f5cb15 100644
--- a/chrome/browser/memory_details.cc
+++ b/chrome/browser/memory_details.cc
@@ -144,8 +144,8 @@ void MemoryDetails::CollectChildInfoOnUIThread() {
       Profile* profile =
           Profile::FromBrowserContext(render_process_host->browser_context());
       ExtensionService* extension_service = profile->GetExtensionService();
-      ExtensionProcessManager* extension_process_manager =
-          profile->GetExtensionProcessManager();
+      extensions::ProcessMap* extension_process_map =
+          extension_service->process_map();
 
       // The RenderProcessHost may host multiple TabContents.  Any
       // of them which contain diagnostics information make the whole
@@ -175,14 +175,25 @@ void MemoryDetails::CollectChildInfoOnUIThread() {
             process.renderer_type = ChildProcessInfo::RENDERER_DEVTOOLS;
           else
             process.renderer_type = ChildProcessInfo::RENDERER_CHROME;
-        } else if (extension_process_manager->AreBindingsEnabledForProcess(
-                   host->process()->id())) {
-          process.renderer_type = ChildProcessInfo::RENDERER_EXTENSION;
+        } else if (extension_process_map->Contains(host->process()->id())) {
+          // For our purposes, don't count processes containing only hosted apps
+          // as extension processes. See also: crbug.com/102533.
+          std::set<std::string> extension_ids =
+              extension_process_map->GetExtensionsInProcess(
+                  host->process()->id());
+          for (std::set<std::string>::iterator iter = extension_ids.begin();
+               iter != extension_ids.end(); ++iter) {
+            const Extension* extension =
+                extension_service->GetExtensionById(*iter, false);
+            if (extension && !extension->is_hosted_app()) {
+              process.renderer_type = ChildProcessInfo::RENDERER_EXTENSION;
+              break;
+            }
+          }
         }
         TabContents* contents = host_delegate->GetAsTabContents();
         if (!contents) {
-          if (extension_process_manager->IsExtensionProcess(
-              host->process()->id())) {
+          if (extension_process_map->Contains(host->process()->id())) {
             const Extension* extension =
                 extension_service->GetExtensionByURL(url);
             if (extension) {
diff --git a/chrome/browser/metrics/metrics_service.cc b/chrome/browser/metrics/metrics_service.cc
index 7f2db89..9a299da 100644
--- a/chrome/browser/metrics/metrics_service.cc
+++ b/chrome/browser/metrics/metrics_service.cc
@@ -156,7 +156,8 @@
 #include "base/values.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/browser_process.h"
-#include "chrome/browser/extensions/extension_process_manager.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/memory_details.h"
 #include "chrome/browser/metrics/histogram_synchronizer.h"
 #include "chrome/browser/metrics/metrics_log.h"
@@ -1243,11 +1244,9 @@ void MetricsService::LogRendererCrash(RenderProcessHost* host,
                                       base::TerminationStatus status,
                                       bool was_alive) {
   Profile* profile = Profile::FromBrowserContext(host->browser_context());
-  ExtensionProcessManager* extension_process_manager =
-      profile->GetExtensionProcessManager();
-  bool was_extension_process = extension_process_manager ?
-      extension_process_manager->IsExtensionProcess(host->id()) :
-      false;
+  ExtensionService* service = profile->GetExtensionService();
+  bool was_extension_process =
+      service && service->process_map()->Contains(host->id());
   if (status == base::TERMINATION_STATUS_PROCESS_CRASHED ||
       status == base::TERMINATION_STATUS_ABNORMAL_TERMINATION) {
     if (was_extension_process)
diff --git a/chrome/browser/profiles/profile.h b/chrome/browser/profiles/profile.h
index 0d32bd0..0e3df82 100644
--- a/chrome/browser/profiles/profile.h
+++ b/chrome/browser/profiles/profile.h
@@ -217,6 +217,10 @@ class Profile : public content::BrowserContext {
   // Return the incognito version of this profile. The returned pointer
   // is owned by the receiving profile. If the receiving profile is off the
   // record, the same profile is returned.
+  //
+  // WARNING: This will create the OffTheRecord profile if it doesn't already
+  // exist. If this isn't what you want, you need to check
+  // HasOffTheRecordProfile() first.
   virtual Profile* GetOffTheRecordProfile() = 0;
 
   // Destroys the incognito profile.
diff --git a/chrome/browser/tab_contents/render_view_host_delegate_helper.cc b/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
index 96c841c..28f4eda 100644
--- a/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
+++ b/chrome/browser/tab_contents/render_view_host_delegate_helper.cc
@@ -16,6 +16,7 @@
 #include "chrome/browser/extensions/extension_process_manager.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_webkit_preferences.h"
+#include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/prerender/prerender_manager.h"
@@ -114,11 +115,11 @@ RenderViewHostDelegateViewHelper::MaybeCreateBackgroundContents(
     return NULL;
 
   // Ensure that we're trying to open this from the extension's process.
-  ExtensionProcessManager* process_manager =
-      profile->GetExtensionProcessManager();
-  if (!site->GetProcess() || !process_manager ||
-      site->GetProcess() != process_manager->GetExtensionProcess(opener_url))
+  extensions::ProcessMap* process_map = extensions_service->process_map();
+  if (!site->GetProcess() ||
+      !process_map->Contains(extension->id(), site->GetProcess()->id())) {
     return NULL;
+  }
 
   // Only allow a single background contents per app. If one already exists,
   // close it (even if it was specified in the manifest).
@@ -542,12 +543,10 @@ WebPreferences RenderViewHostDelegateHelper::GetWebkitPrefs(
 
   web_prefs.is_online = !net::NetworkChangeNotifier::IsOffline();
 
-  ExtensionProcessManager* extension_process_manager =
-      profile->GetExtensionProcessManager();
-  if (extension_process_manager) {
+  ExtensionService* service = profile->GetExtensionService();
+  if (service) {
     const Extension* extension =
-        extension_process_manager->GetExtensionForSiteInstance(
-            rvh->site_instance()->id());
+        service->GetExtensionByURL(rvh->site_instance()->site());
     extension_webkit_preferences::SetPreferences(&web_prefs, extension);
   }
 
diff --git a/chrome/browser/task_manager/task_manager_resource_providers.cc b/chrome/browser/task_manager/task_manager_resource_providers.cc
index fb2f2ed..7094b64 100644
--- a/chrome/browser/task_manager/task_manager_resource_providers.cc
+++ b/chrome/browser/task_manager/task_manager_resource_providers.cc
@@ -267,13 +267,11 @@ string16 TaskManagerTabContentsResource::GetTitle() const {
   // Only classify as an app if the URL is an app and the tab is hosting an
   // extension process.  (It's possible to be showing the URL from before it
   // was installed as an app.)
-  ExtensionService* extensions_service =
+  ExtensionService* extension_service =
       tab_contents_->profile()->GetExtensionService();
-  ExtensionProcessManager* extension_process_manager =
-      tab_contents_->profile()->GetExtensionProcessManager();
-  bool is_app = extensions_service->IsInstalledApp(url) &&
-      extension_process_manager->IsExtensionProcess(
-          contents->GetRenderProcessHost()->id());
+  extensions::ProcessMap* process_map = extension_service->process_map();
+  bool is_app = extension_service->IsInstalledApp(url) &&
+      process_map->Contains(contents->GetRenderProcessHost()->id());
 
   int message_id = GetMessagePrefixID(
       is_app,
@@ -306,9 +304,9 @@ TabContentsWrapper* TaskManagerTabContentsResource::GetTabContents() const {
 
 const Extension* TaskManagerTabContentsResource::GetExtension() const {
   if (HostsExtension()) {
-    ExtensionService* extensions_service =
+    ExtensionService* extension_service =
         tab_contents_->profile()->GetExtensionService();
-    return extensions_service->GetExtensionByURL(
+    return extension_service->GetExtensionByURL(
         tab_contents_->tab_contents()->GetURL());
   }
 
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 569a004..53e86cb 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1250,6 +1250,8 @@
         'browser/extensions/pending_extension_info.h',
         'browser/extensions/pending_extension_manager.cc',
         'browser/extensions/pending_extension_manager.h',
+        'browser/extensions/process_map.cc',
+        'browser/extensions/process_map.h',
         'browser/extensions/sandboxed_extension_unpacker.cc',
         'browser/extensions/sandboxed_extension_unpacker.h',
         'browser/extensions/speech_input/extension_speech_input_api.cc',
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 939dfa6..a292bd8 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -1367,6 +1367,7 @@
         'browser/extensions/in_memory_extension_settings_storage_unittest.cc',
         'browser/extensions/key_identifier_conversion_views_unittest.cc',
         'browser/extensions/network_delay_listener_unittest.cc',
+        'browser/extensions/process_map_unittest.cc',
         'browser/extensions/sandboxed_extension_unpacker_unittest.cc',
         'browser/extensions/user_script_listener_unittest.cc',
         'browser/extensions/user_script_master_unittest.cc',
diff --git a/content/browser/mock_content_browser_client.cc b/content/browser/mock_content_browser_client.cc
index ed558df..98b8ecd 100644
--- a/content/browser/mock_content_browser_client.cc
+++ b/content/browser/mock_content_browser_client.cc
@@ -79,6 +79,14 @@ bool MockContentBrowserClient::IsSuitableHost(
   return true;
 }
 
+void MockContentBrowserClient::SiteInstanceGotProcess(
+    SiteInstance* site_instance) {
+}
+
+void MockContentBrowserClient::SiteInstanceDeleting(
+    SiteInstance* site_instance) {
+}
+
 bool MockContentBrowserClient::ShouldSwapProcessesForNavigation(
     const GURL& current_url,
     const GURL& new_url) {
diff --git a/content/browser/mock_content_browser_client.h b/content/browser/mock_content_browser_client.h
index 79e700c..23d53b1 100644
--- a/content/browser/mock_content_browser_client.h
+++ b/content/browser/mock_content_browser_client.h
@@ -42,6 +42,8 @@ class MockContentBrowserClient : public ContentBrowserClient {
   virtual bool IsURLSameAsAnySiteInstance(const GURL& url) OVERRIDE;
   virtual bool IsSuitableHost(RenderProcessHost* process_host,
                               const GURL& site_url) OVERRIDE;
+  virtual void SiteInstanceGotProcess(SiteInstance* site_instance) OVERRIDE;
+  virtual void SiteInstanceDeleting(SiteInstance* site_instance) OVERRIDE;
   virtual bool ShouldSwapProcessesForNavigation(const GURL& current_url,
                                                 const GURL& new_url) OVERRIDE;
   virtual std::string GetCanonicalEncodingNameByAliasName(
diff --git a/content/browser/site_instance.cc b/content/browser/site_instance.cc
index ad79d74..d41f49b 100644
--- a/content/browser/site_instance.cc
+++ b/content/browser/site_instance.cc
@@ -42,10 +42,7 @@ SiteInstance::SiteInstance(BrowsingInstance* browsing_instance)
 }
 
 SiteInstance::~SiteInstance() {
-  content::NotificationService::current()->Notify(
-      content::NOTIFICATION_SITE_INSTANCE_DELETED,
-      content::Source<SiteInstance>(this),
-      content::NotificationService::NoDetails());
+  content::GetContentClient()->browser()->SiteInstanceDeleting(this);
 
   // Now that no one is referencing us, we can safely remove ourselves from
   // the BrowsingInstance.  Any future visits to a page from this site
@@ -84,6 +81,8 @@ RenderProcessHost* SiteInstance::GetProcess() {
       }
     }
 
+    content::GetContentClient()->browser()->SiteInstanceGotProcess(this);
+
     // Make sure the process starts at the right max_page_id
     process_->UpdateMaxPageID(max_page_id_);
   }
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index a404112..727e6c9 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -29,6 +29,7 @@ class RenderViewHost;
 class RenderWidgetHost;
 class RenderWidgetHostView;
 class ResourceDispatcherHost;
+class SiteInstance;
 class SSLCertErrorHandler;
 class SSLClientAuthHandler;
 class SkBitmap;
@@ -145,6 +146,12 @@ class ContentBrowserClient {
   virtual bool IsSuitableHost(RenderProcessHost* process_host,
                               const GURL& site_url) = 0;
 
+  // Called when a site instance is first associated with a process.
+  virtual void SiteInstanceGotProcess(SiteInstance* site_instance) = 0;
+
+  // Called from a site instance's destructor.
+  virtual void SiteInstanceDeleting(SiteInstance* site_instance) = 0;
+
   // Returns true if for the navigation from |current_url| to |new_url|,
   // processes should be swapped (even if we are in a process model that
   // doesn't usually swap).
diff --git a/content/public/browser/notification_types.h b/content/public/browser/notification_types.h
index c0e465d..1d6e503 100644
--- a/content/public/browser/notification_types.h
+++ b/content/public/browser/notification_types.h
@@ -356,10 +356,6 @@ enum NotificationType {
   // the new state is "visible."
   NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
 
-  // Sent from ~SiteInstance.  The source is the SiteInstance, and the details
-  // are unused.
-  NOTIFICATION_SITE_INSTANCE_DELETED,
-
   // The focused element inside a page has changed.  The source is the
   // TabContents containing the render view host for the page. The details is
   // a Details<const bool> that indicates whether or not an editable node was
diff --git a/content/shell/shell_content_browser_client.cc b/content/shell/shell_content_browser_client.cc
index 1379e82..2a31c9a 100644
--- a/content/shell/shell_content_browser_client.cc
+++ b/content/shell/shell_content_browser_client.cc
@@ -93,6 +93,14 @@ bool ShellContentBrowserClient::IsSuitableHost(
   return true;
 }
 
+void ShellContentBrowserClient::SiteInstanceGotProcess(
+    SiteInstance* site_instance) {
+}
+
+void ShellContentBrowserClient::SiteInstanceDeleting(
+    SiteInstance* site_instance) {
+}
+
 bool ShellContentBrowserClient::ShouldSwapProcessesForNavigation(
     const GURL& current_url,
     const GURL& new_url) {
diff --git a/content/shell/shell_content_browser_client.h b/content/shell/shell_content_browser_client.h
index 2e44aa9..e8aa52f 100644
--- a/content/shell/shell_content_browser_client.h
+++ b/content/shell/shell_content_browser_client.h
@@ -54,6 +54,8 @@ class ShellContentBrowserClient : public ContentBrowserClient
   virtual bool IsURLSameAsAnySiteInstance(const GURL& url) OVERRIDE;
   virtual bool IsSuitableHost(RenderProcessHost* process_host,
                               const GURL& site_url) OVERRIDE;
+  virtual void SiteInstanceGotProcess(SiteInstance* site_instance) OVERRIDE;
+  virtual void SiteInstanceDeleting(SiteInstance* site_instance) OVERRIDE;
   virtual bool ShouldSwapProcessesForNavigation(const GURL& current_url,
                                                 const GURL& new_url) OVERRIDE;