Fixing data_deps on Mac for content_shell

Temporary fix to check if this ends up with the mojo.js generated
files get correctly included.

BUG=717344
TBR=dpranke@chromium.org,jochen@chromium.org,mcgreevy@chromium.org

Review-Url: https://codereview.chromium.org/2926843002
Cr-Commit-Position: refs/heads/master@{#477918}

content/shell/BUILD.gn

@@ -500,6 +500,9 @@ if (is_android) {
       "@executable_path/../",
     ]
     info_plist_target = ":content_shell_plist"
+    data_deps = [
+      ":content_shell_lib",
+    ]
   }
 } else {
   executable("content_shell") {