Use MailboxManagerSync on android.

services/gles2/gpu_state.cc

Index: services/gles2/gpu_state.cc
diff --git a/services/gles2/gpu_state.cc b/services/gles2/gpu_state.cc
index 47439fe451415a62fbba34f056f07d423ba82300..911477114cea8a9dc0b48a6fb7a654ccf5c386f8 100644
--- a/services/gles2/gpu_state.cc
+++ b/services/gles2/gpu_state.cc
@@ -5,13 +5,15 @@
 
 #include "services/gles2/gpu_state.h"
 
+#include "services/gles2/mailbox_manager_factory.h"
+
 namespace gles2 {
 
 GpuState::GpuState()
     : control_thread_("gpu_command_buffer_control"),
       sync_point_manager_(gpu::SyncPointManager::Create(true)),
       share_group_(new gfx::GLShareGroup),
-      mailbox_manager_(new gpu::gles2::MailboxManagerImpl) {
+      mailbox_manager_(MailboxManagerFactory::Create()) {
   control_thread_.Start();
 }