gpu: Add ARB_occlusion_query support.

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 7f49bd2f61f1d5e5c96eb4bcddb759db8d91fc6c..1812ad0c3493b1ceb3bcce9da259231b951f18a9 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -5550,12 +5550,20 @@ void GLES2Implementation::BeginQueryEXT(GLenum target, GLuint id) {
         return;
       }
       break;
+    case GL_SAMPLES_PASSED_ARB:
+      if (!capabilities_.occlusion_query) {
+        SetGLError(
+            GL_INVALID_OPERATION, "glBeginQueryEXT",
+            "not enabled for occlusion queries");
+        return;
+      }
+      break;
     case GL_ANY_SAMPLES_PASSED:
     case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
       if (!capabilities_.occlusion_query_boolean) {
         SetGLError(
             GL_INVALID_OPERATION, "glBeginQueryEXT",
-            "not enabled for occlusion queries");
+            "not enabled for boolean occlusion queries");
         return;
       }
       break;