Revert 24846 - Enable extensions by default....

chrome/browser/renderer_host/browser_render_process_host.cc

 // Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "chrome/browser/renderer_host/browser_render_process_host.h"
 
 #include "build/build_config.h"
@@ skipping 331 matching lines @@
     switches::kEnableDatabases,
   };
 
   for (size_t i = 0; i < arraysize(switch_names); ++i) {
     if (browser_command_line.HasSwitch(switch_names[i])) {
       cmd_line.AppendSwitchWithValue(switch_names[i],
           browser_command_line.GetSwitchValue(switch_names[i]));
     }
   }
 
+  // Tell the renderer to enable extensions if there are any extensions loaded.
+  //
+  // NOTE: This is subtly different than just passing along whether
+  // --enable-extenisons is present in the browser process. For example, there
+  // is also an extensions.enabled preference, and there may be various special
+  // cases about whether to allow extensions to load.
+  //
+  // This introduces a race condition where the first renderer never gets
+  // extensions enabled, so we also set the flag if extensions_enabled(). This
+  // isn't perfect though, because of the special cases above.
+  //
+  // TODO(aa): We need to get rid of the need to pass this flag at all. It is
+  // only used in one place in the renderer.
+  if (profile()->GetExtensionsService()) {
+    if (profile()->GetExtensionsService()->extensions()->size() > 0 ||
+        profile()->GetExtensionsService()->extensions_enabled())
+      cmd_line.AppendSwitch(switches::kEnableExtensions);
+  }
+
   // Pass on the browser locale.
   const std::string locale = g_browser_process->GetApplicationLocale();
   cmd_line.AppendSwitchWithValue(switches::kLang, ASCIIToWide(locale));
 
   // If we run FieldTrials, we want to pass to their state to the renderer so
   // that it can act in accordance with each state, or record histograms
   // relating to the FieldTrial states.
   std::string field_trial_states;
   FieldTrialList::StatesToString(&field_trial_states);
   if (!field_trial_states.empty())
@@ skipping 597 matching lines @@
     profile()->GetExtensionMessageService()->RemoveEventListener(
         event_name, id());
   }
 }
 
 void BrowserRenderProcessHost::OnExtensionCloseChannel(int port_id) {
   if (profile()->GetExtensionMessageService()) {
     profile()->GetExtensionMessageService()->CloseChannel(port_id);
   }
 }