DevTools: Use jsdocs @template in InjectedScriptCanvasModuleSource.js.

BUG=
TBR=pfeldman,vsevik

Review URL: https://codereview.chromium.org/19803002

git-svn-id: svn://svn.chromium.org/blink/trunk@154566 bbb929c8-8fbe-4397-9dbb-9b2b20218538