Revert 238244 "Removed the protected content exceptions button."

> Removed the protected content exceptions button.
> 
> This feature has not landed, the button should not be shown.
> 
> BUG=chromium:324078
> TEST=manual
> R=mukai@chromium.org
> 
> Review URL: https://codereview.chromium.org/93273002

TBR=dkrahn@chromium.org

Review URL: https://codereview.chromium.org/98493006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238839 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238839
gpu: Add IOSurface backed GpuMemoryBuffer implementation.
    
This adds a GpuMemoryBuffer implementation on MacOSX that is backed
by IOSurfaces. These GpuMemmoryBuffers provide zero-copy texture
updates when using impl-side painting on MacOSX.
    
BUG=321785,323338

Review URL: https://codereview.chromium.org/77023002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238841 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238841