Make extensions use ViewMsg_EnableIntrinsicWidthChangedMode.

chrome/browser/extensions/extension_host.cc

Index: chrome/browser/extensions/extension_host.cc
diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index 168e002f163928d4a4ae870bbf296ddc3e7f0049..ed71dc9ef98ac7a12e189e9054a8a2662c615d1f 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -345,6 +345,9 @@ void ExtensionHost::RenderViewCreated(RenderViewHost* render_view_host) {
   // See http://code.google.com/p/chromium/issues/detail?id=18240
   extension_function_dispatcher_.reset(
       new ExtensionFunctionDispatcher(render_view_host, this, url_));
+
+  render_view_host->Send(new ViewMsg_EnableIntrinsicWidthChangedMode(
+      render_view_host->routing_id()));
 }
 
 int ExtensionHost::GetBrowserWindowID() const {