aura: Create a new FrameProvider when frame size in DIP changes.

When the renderer gives the UI a new frame that has the same number
of physical pixels but a new scale factor, we must display the frame
at a new scale in the UI.

In order to do this, we replace the FrameProvider entirely to use the
same path that we would use when the frame changed size (ie number of
pixels). This should help ensure that the new scale given to the ui::Layer
will be shown in sync with the new frame texture regardless of future
commit-less update type optimizations.

Test: RenderWidgetHostViewAuraTest.SoftwareDPIChange

R=piman
BUG=318410

Review URL: https://codereview.chromium.org/107143003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239234 0039d316-1c4b-4281-b951-d872f2087c98
Support custom serial bitrates on OS X

BUG=243097

Review URL: https://codereview.chromium.org/107363002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239235 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239235
Disable media.tough_media_cases on Win8

BUG=326384
NOTRY=true

Review URL: https://codereview.chromium.org/108583002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239236 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239236