2 files changed, 19 insertions, 4 deletions
diff --git a/ppapi/proxy/plugin_globals.cc b/ppapi/proxy/plugin_globals.cc
index 75369d0..79e7383 100644
--- a/ppapi/proxy/plugin_globals.cc
+++ b/ppapi/proxy/plugin_globals.cc
@@ -20,6 +20,12 @@ PluginGlobals::PluginGlobals()
       callback_tracker_(new CallbackTracker),
       loop_for_main_thread_(
           new MessageLoopResource(MessageLoopResource::ForMainThread())) {
+#if defined(ENABLE_PEPPER_THREADING)
+  enable_threading_ = true;
+#else
+  enable_threading_ = false;
+#endif
+
   DCHECK(!plugin_globals_);
   plugin_globals_ = this;
 }
@@ -28,6 +34,11 @@ PluginGlobals::PluginGlobals(ForTest for_test)
     : ppapi::PpapiGlobals(for_test),
       plugin_proxy_delegate_(NULL),
       callback_tracker_(new CallbackTracker) {
+#if defined(ENABLE_PEPPER_THREADING)
+  enable_threading_ = true;
+#else
+  enable_threading_ = false;
+#endif
   DCHECK(!plugin_globals_);
 }
 
@@ -80,11 +91,9 @@ void PluginGlobals::PreCacheFontForFlash(const void* logfontw) {
 }
 
 base::Lock* PluginGlobals::GetProxyLock() {
-#ifdef ENABLE_PEPPER_THREADING
-  return &proxy_lock_;
-#else
+  if (enable_threading_)
+    return &proxy_lock_;
   return NULL;
-#endif
 }
 
 void PluginGlobals::LogWithSource(PP_Instance instance,
diff --git a/ppapi/proxy/plugin_globals.h b/ppapi/proxy/plugin_globals.h
index 215ad63..c8bf113 100644
--- a/ppapi/proxy/plugin_globals.h
+++ b/ppapi/proxy/plugin_globals.h
@@ -100,6 +100,10 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
   // The embedder should call this function when the command line is known.
   void set_command_line(const std::string& c) { command_line_ = c; }
 
+  // Sets whether threadsafety is supported. Defaults to whether the
+  // ENABLE_PEPPER_THREADING build flag is set.
+  void set_enable_threading(bool enable) { enable_threading_ = enable; }
+
  private:
   // PpapiGlobals overrides.
   virtual bool IsPluginGlobals() const OVERRIDE;
@@ -110,6 +114,8 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
   PluginResourceTracker plugin_resource_tracker_;
   PluginVarTracker plugin_var_tracker_;
   scoped_refptr<CallbackTracker> callback_tracker_;
+
+  bool enable_threading_;  // Indicates whether we'll use the lock.
   base::Lock proxy_lock_;
 
   scoped_ptr<base::ThreadLocalStorage::Slot> msg_loop_slot_;