DevTools: Add JSDoc for static methods, fix JSDoc types and induced errors

This patch adds JSDoc for "WebInspector.Foo.bar" methods and fixes
induced errors:
- adds typecasts where required;
- removes unused code violating JSDoc, which was not checked previously;
- adds missing "useCapture" addEventListener() arguments (they are
  required by the current compiler and will be fixed after the
  compiler roll).

R=yurys@chromium.org, vsevik, yurys

Review URL: https://codereview.chromium.org/340513003

git-svn-id: svn://svn.chromium.org/blink/trunk@176325 bbb929c8-8fbe-4397-9dbb-9b2b20218538