Revert update because experimental i18n extension broke the build.

Review URL: http://codereview.chromium.org/7060004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86264 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -17,7 +17,7 @@ vars = {
   "libvpx_revision": "81610",
   "ffmpeg_revision": "83815",
   "skia_revision": "1395",
-  "v8_revision": "7975",
+  "v8_revision": "7928",
 }
 
 deps = {