Update to Chromium revision 9cedf753 (#418732)

- Simplify usage of OnBeforePluginLoad (issue #2015)
- Switch crash reporting from crashpad to breakpad on Windows and OS X.
  Adds a new chrome_elf.dll dependency on Windows (issue #1995)
- Remove CefTextfield::GetPlaceholderTextColor() method which is no
  longer supported by Chromium.

libcef/browser/extensions/api/tabs/tabs_api.cc

@@ -26,6 +26,8 @@ namespace tabs = api::tabs;
 
 namespace {
 
+const char kNotImplementedError[] = "Not implemented";
+
 // Any out parameter (|browser|, |contents|, & |tab_index|) may be NULL and will
 // not be set within the function.
 // Based on ExtensionTabUtil::GetTabById().
@@ -124,6 +126,10 @@ void ZoomModeToZoomSettings(zoom::ZoomController::ZoomMode zoom_mode,
 
 }  // namespace
 
+ExtensionFunction::ResponseAction TabsGetFunction::Run() {
+  return RespondNow(Error(kNotImplementedError));
+}
+
 content::WebContents* ZoomAPIFunction::GetWebContents(int tab_id) {
   content::WebContents* web_contents = NULL;
   if (tab_id != -1) {