ResourceProvider should be able to avoid allocating immutable textures.

copyTexImage2D will fail when called on a texture having immutable
storage, allocated using texStorage2DEXT.
I encountered this problem while working on mix-blend-mode in cc:
http://crrev.com/23455060#msg51.

This problem is valid for background filters as well. Background filters
unittests pass because the test framework uses mesa, which does not
support texture storage. I couldn't create cc_unittests for the same
reason.
Texture storage currently is supported on windows using angle by
default.


BUG=243223

Review URL: https://codereview.chromium.org/79603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236482 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236482