Roll clang 137532:137560

This picks up support for -x objc++-cpp-output, which ccache needs.

BUG=92793
TEST=none
TBR=hans

Review URL: http://codereview.chromium.org/7645013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96706 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -28,7 +28,7 @@ vars = {
 
   # Note: On most bots, clang is not checked out via DEPS but by
   # tools/clang/scripts/update.sh. The script reads this line here.
-  "clang_revision": "137532",
+  "clang_revision": "137560",
 }
 
 deps = {