Don't send unnecessary ExtensionMsg_Loaded IPCs.

extensions/browser/extension_web_contents_observer.cc

 // Copyright 2014 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 "extensions/browser/extension_web_contents_observer.h"
 
 #include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
@@ skipping 72 matching lines @@
   // Some extensions use file:// URLs.
   if (type == Manifest::TYPE_EXTENSION ||
       type == Manifest::TYPE_LEGACY_PACKAGED_APP) {
     ExtensionPrefs* prefs = ExtensionPrefs::Get(browser_context_);
     if (prefs->AllowFileAccess(extension->id())) {
       content::ChildProcessSecurityPolicy::GetInstance()->GrantScheme(
           process->GetID(), url::kFileScheme);
     }
   }
 
-  switch (type) {
-    case Manifest::TYPE_EXTENSION:
-    case Manifest::TYPE_USER_SCRIPT:
-    case Manifest::TYPE_HOSTED_APP:
-    case Manifest::TYPE_LEGACY_PACKAGED_APP:
-    case Manifest::TYPE_PLATFORM_APP:
-      // Always send a Loaded message before ActivateExtension so that
-      // ExtensionDispatcher knows what Extension is active, not just its ID.
-      // This is important for classifying the Extension's JavaScript context
-      // correctly (see ExtensionDispatcher::ClassifyJavaScriptContext).
-      // We also have to include the tab-specific permissions here, since it's
-      // an extension process.
-      render_view_host->Send(
-          new ExtensionMsg_Loaded(std::vector<ExtensionMsg_Loaded_Params>(
-              1, ExtensionMsg_Loaded_Params(
-                     extension, true /* include tab permissions */))));
-      render_view_host->Send(
-          new ExtensionMsg_ActivateExtension(extension->id()));
-      break;
-
-    case Manifest::TYPE_UNKNOWN:
-    case Manifest::TYPE_THEME:
-    case Manifest::TYPE_SHARED_MODULE:
-      break;
-
-    case Manifest::NUM_LOAD_TYPES:
-      NOTREACHED();
-  }
+  // Tells the new view that it's hosted in an extension process.
+  //
+  // This will often be a rendant IPC, because activating extensions happens at
+  // the process level, not at the view level. However, without some mild
+  // refactoring this isn't trivial to do, and this way is simpler.
+  //
+  // Plus, we can delete the concept of activating an extension once site
+  // isolation is turned on.
+  render_view_host->Send(new ExtensionMsg_ActivateExtension(extension->id()));
 }
 
 void ExtensionWebContentsObserver::RenderFrameCreated(
     content::RenderFrameHost* render_frame_host) {
   const Extension* extension = GetExtensionForRenderFrame(render_frame_host);
   if (extension) {
     ExtensionsBrowserClient::Get()->RegisterMojoServices(render_frame_host,
                                                          extension);
   }
 }
@@ skipping 62 matching lines @@
   // site, so we can ignore that wrinkle here.
   const GURL& site = render_view_host->GetSiteInstance()->GetSiteURL();
 
   if (!site.SchemeIs(kExtensionScheme))
     return std::string();
 
   return site.host();
 }
 
 }  // namespace extensions