Do not build libpng when instrumenting libraries with ThreadSanitizer

TBR=earthdok@chromium.org
BUG=313751
NOTRY=true

Review URL: https://codereview.chromium.org/285713002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270137 0039d316-1c4b-4281-b951-d872f2087c98

third_party/instrumented_libraries/instrumented_libraries.gyp

@@ -102,6 +102,11 @@
             '<(_sanitizer_type)-libcups2',
           ],
         }],
+        ['tsan==1', {
+          'dependencies!': [
+            '<(_sanitizer_type)-libpng12-0',
+          ],
+        }],
       ],
       'actions': [
         {