PPAPI: Make tests that disable the proxy lock re-enable it

ppapi/shared_impl/proxy_lock.h

Index: ppapi/shared_impl/proxy_lock.h
diff --git a/ppapi/shared_impl/proxy_lock.h b/ppapi/shared_impl/proxy_lock.h
index 23afc0e5506e5160b575e08735e44413c0ddbdfb..39b653e1a00bccb49217f9b494d4d5a666d5a67d 100644
--- a/ppapi/shared_impl/proxy_lock.h
+++ b/ppapi/shared_impl/proxy_lock.h
@@ -59,12 +59,11 @@ class PPAPI_SHARED_EXPORT ProxyLock {
   // We have some unit tests where one thread pretends to be the host and one
   // pretends to be the plugin. This allows the lock to do nothing on only one
   // thread to support these tests. See TwoWayTest for more information.
-  static void DisableLockingOnThreadForTest();
-
-  // Enables locking on the current thread. Although locking is enabled by
-  // default, unit tests that rely on the lock being enabled should *still*
-  // call this, since a previous test may have disabled locking.
-  static void EnableLockingOnThreadForTest();
+  class PPAPI_SHARED_EXPORT LockingDisablerForTest {
+   public:
+    LockingDisablerForTest();
+    ~LockingDisablerForTest();
+  };
 
  private:
   friend class content::HostGlobals;