Code:  TabsCustomBindings::TabsCustomBindings(ScriptContext* context)
     : ObjectBackedNativeHandler(context) {
  RouteFunction("OpenChannelToTab",
      base::Bind(&TabsCustomBindings::OpenChannelToTab,
                 base::Unretained(this)));
 }

Vulnerability Type: Bypass 
CWE ID: CWE-284
Summary: The extensions subsystem in Google Chrome before 51.0.2704.79 does not properly restrict bindings access, which allows remote attackers to bypass the Same Origin Policy via unspecified vectors.
Commit Message: [Extensions] Expand bindings access checks

BUG=601149
BUG=601073

Review URL: https://codereview.chromium.org/1866103002

Cr-Commit-Position: refs/heads/master@{#387710}