gpu: Add ARB_occlusion_query support.

gpu/command_buffer/service/query_manager.cc

Index: gpu/command_buffer/service/query_manager.cc
diff --git a/gpu/command_buffer/service/query_manager.cc b/gpu/command_buffer/service/query_manager.cc
index a5071e335d7ad1cb9088f785168894d98293e995..9c1ac4280a80125c003b9dcb093da448f2262930 100644
--- a/gpu/command_buffer/service/query_manager.cc
+++ b/gpu/command_buffer/service/query_manager.cc
@@ -803,6 +803,9 @@ QueryManager::Query* QueryManager::CreateQuery(GLenum target,
     case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
       query = new SummedIntegerQuery(this, target, shm_id, shm_offset);
       break;
+    case GL_SAMPLES_PASSED:
+      query = new SummedIntegerQuery(this, target, shm_id, shm_offset);
+      break;
     default: {
       NOTREACHED();
     }