Cause the MemoryHolder to be destroyed before the member variables of the RWHVA are.

The framebuffer_holder_'s destructor, which modifies released_software_frames_ was run after released_software_frames_'s destructor, which causes problems.

BUG=
R=piman@chromium.org

Review URL: https://codereview.chromium.org/24920002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225747 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225747