Android: moves base_unittests_jni_headers to use long for JNI.

BUG=317523

Review URL: https://codereview.chromium.org/131523002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243908 0039d316-1c4b-4281-b951-d872f2087c98

base/base.gyp

@@ -1222,6 +1222,7 @@
           ],
           'variables': {
             'jni_gen_package': 'base',
+            'jni_generator_ptr_type': 'long',
           },
           'includes': [ '../build/jni_generator.gypi' ],
         },