Enable occlusion query feature on OpenGL3.3 and later

gpu/command_buffer/service/feature_info.cc

Index: gpu/command_buffer/service/feature_info.cc
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index 413e11d39f10a84c9707f07f8cdd999aa20933dc..44ddbc6ce492017e77d45a1edbd5e8bf308fa906 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -106,6 +106,8 @@ FeatureInfo::FeatureFlags::FeatureFlags()
       occlusion_query_boolean(false),
       use_arb_occlusion_query2_for_occlusion_query_boolean(false),
       use_arb_occlusion_query_for_occlusion_query_boolean(false),
+      no_covert_any_samples_passed_conservative_target_for_es3(false),
+      covert_any_samples_passed_conservative_target_for_low_gl(false),
       native_vertex_array_object(false),
       ext_texture_format_astc(false),
       ext_texture_format_atc(false),
@@ -1044,8 +1046,9 @@ void FeatureInfo::InitializeFeatures() {
     }
   }
 
-  bool have_es3_occlusion_query =
-      gl_version_info_->IsAtLeastGLES(3, 0);
+  bool have_occlusion_query =
+      gl_version_info_->IsAtLeastGLES(3, 0) ||
+      gl_version_info_->IsAtLeastGL(3, 3);
   bool have_ext_occlusion_query_boolean =
       extensions.Contains("GL_EXT_occlusion_query_boolean");
   bool have_arb_occlusion_query2 =
@@ -1053,7 +1056,7 @@ void FeatureInfo::InitializeFeatures() {
   bool have_arb_occlusion_query =
       extensions.Contains("GL_ARB_occlusion_query");
 
-  if (have_es3_occlusion_query ||
+  if (have_occlusion_query ||
       have_ext_occlusion_query_boolean ||
       have_arb_occlusion_query2 ||
       have_arb_occlusion_query) {
@@ -1066,6 +1069,11 @@ void FeatureInfo::InitializeFeatures() {
     feature_flags_.use_arb_occlusion_query_for_occlusion_query_boolean =
         !have_ext_occlusion_query_boolean && have_arb_occlusion_query &&
         !have_arb_occlusion_query2;
+    feature_flags_.no_covert_any_samples_passed_conservative_target_for_es3 =

[Zhenyao Mo, 2016/07/14 18:09:02]

I don't think you need two new flags for this purpose.  You only need to specify
three behaviors

1) core bahavior, either ES3+, or GL4.3+, or have ext_occlusion_query_boolean.

2) arb_occlusion_query2 behavior, not 1, and have arb_occlusion_query2

3) arb_occulision_query bahavior, not 1, and no arb_occlusion_query2, and have
arb_occlusion_query

And you only need two flags (no flag means no mapping, the core behavior).

Hope I explained myself clearly.

+        gl_version_info_->IsAtLeastGLES(3, 0);
+    feature_flags_.covert_any_samples_passed_conservative_target_for_low_gl =
+        gl_version_info_->IsAtLeastGL(3, 3) &&
+        gl_version_info_->IsLowerThanGL(4, 3);
   }
 
   if (!workarounds_.disable_angle_instanced_arrays &&