Replace some string16's with base namespace in chrome/browser

TBR=sky

Review URL: https://codereview.chromium.org/101953005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240126 0039d316-1c4b-4281-b951-d872f2087c98
Make ContentRendererClient's OverrideCreatePlugin and CreatePluginReplacement take only a RenderFrame.

In two places I called the temporary method render_frame->GetRenderView() because ContentSettingsObserver still has to be switched to be a RenderFrameObserver.

BUG=304341
R=bauerb@chromium.org, nasko@chromium.org

Review URL: https://codereview.chromium.org/106973012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240127 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240127