Add media_cdm_adapter.gyp: a common base for all CDM adapters.

This removes duplicate code in CDM adapter gyp targets.

Also move more code under the condition enable_pepper_cdms==1 so that when enable_pepper_cdms==0, clearkeycdm, clearkeycdmadapter and widevinecdmadapter targets won't exist.

BUG=329097
TEST=Widevine and ClearKey CDM adapters still work.

Review URL: https://codereview.chromium.org/108703004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241736 0039d316-1c4b-4281-b951-d872f2087c98
Disable NaClBrowserTest.PPAPIPPPInstance.

This has been failing flakily in its NaClBrowserTestPnacl.PPAPIPPPInstance
incarnation, and in others as well according to the description
on the bug. The earliest instance of a failure I saw on the
flakiness dashboard was 12/13/2013 7:41:03 AM. That dashboard
is here: http://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=browser_tests&tests=NaClBrowserTestPnacl.PPAPIPPPInstance

TBR=ncbray@chromium.org
BUG=329511

Review URL: https://codereview.chromium.org/117393005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241737 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241737