Fix for MIME handler bug.

extensions/renderer/guest_view/guest_view_internal_custom_bindings.cc

Index: extensions/renderer/guest_view/guest_view_internal_custom_bindings.cc
diff --git a/extensions/renderer/guest_view/guest_view_internal_custom_bindings.cc b/extensions/renderer/guest_view/guest_view_internal_custom_bindings.cc
index 49dae796c2e27425c25b40e0a971df453ad28f85..ff18e04b603620b913a01d0bf9871804bf3ebbea 100644
--- a/extensions/renderer/guest_view/guest_view_internal_custom_bindings.cc
+++ b/extensions/renderer/guest_view/guest_view_internal_custom_bindings.cc
@@ -11,6 +11,7 @@
 #include "content/public/renderer/render_view.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_messages.h"
+#include "extensions/common/guest_view/guest_view_constants.h"
 #include "extensions/renderer/guest_view/extensions_guest_view_container.h"
 #include "extensions/renderer/script_context.h"
 #include "v8/include/v8.h"
@@ -74,6 +75,10 @@ void GuestViewInternalCustomBindings::AttachGuest(
         static_cast<base::DictionaryValue*>(params_as_value.release()));
   }
 
+  // Add flag to |params| to indicate that the element size is specified in
+  // logical units.
+  params->SetBoolean(guestview::kElementSizeIsLogical, true);
+
   linked_ptr<ExtensionsGuestViewContainer::Request> request(
       new ExtensionsGuestViewContainer::AttachRequest(
           guest_view_container,