DevTools: [JsDocValidator] Validate InjectedScriptCanvasModuleSource and InjectedScriptSource

R=aandrey, vsevik

Review URL: https://codereview.chromium.org/376863004

git-svn-id: svn://svn.chromium.org/blink/trunk@177667 bbb929c8-8fbe-4397-9dbb-9b2b20218538