Change quota::QuotaClient::kAllClientsMask to be an enum.

By the standard, static constants should also have a definition counterpart to
allocate storage space. It's not strictly necessary for ints (but it puts usage
restrictions on them), and for some reason we are having linking failure on
Chrome on Android when building with clang compiler, maybe that's because of
using templates or perhaps it's a clang issue.

Anyway, converting this constant into an enum solves the problem.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/9585014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124711 0039d316-1c4b-4281-b951-d872f2087c98

webkit/quota/quota_client.h

@@ -35,10 +35,9 @@ class QuotaClient {
     kDatabase = 1 << 2,
     kAppcache = 1 << 3,
     kIndexedDatabase = 1 << 4,
+    kAllClientsMask = -1,
   };
 
-  static const int kAllClientsMask = -1;
-
   virtual ID id() const = 0;
 
   // Called when the quota manager is destroyed.