remove 'unsafe' from ES3 apis in gpu process

gpu/command_buffer/service/context_group.cc

Index: gpu/command_buffer/service/context_group.cc
diff --git a/gpu/command_buffer/service/context_group.cc b/gpu/command_buffer/service/context_group.cc
index 539758427695de011d2356b3860b9549633ffc1d..0e0c27c5efc433637b4f10f1c87038a4d6b1a531 100644
--- a/gpu/command_buffer/service/context_group.cc
+++ b/gpu/command_buffer/service/context_group.cc
@@ -118,6 +118,16 @@ ContextGroup::ContextGroup(
 bool ContextGroup::Initialize(GLES2Decoder* decoder,
                               ContextType context_type,
                               const DisallowedFeatures& disallowed_features) {
+  if (!gpu_preferences_.enable_unsafe_es3_apis) {
+    if (context_type == CONTEXT_TYPE_OPENGLES3) {
+      context_type = CONTEXT_TYPE_OPENGLES2;

[Zhenyao Mo, 2016/11/02 22:49:57]

You should print out a DLOG as the WEBGL2 case. No need to change context_type.

+      return false;
+    } else if (context_type == CONTEXT_TYPE_WEBGL2) {
+      DLOG(ERROR) << "ContextGroup::Initialize failed because WebGL 2 is not "
+                  << "available.";
+      return false;
+    }
+  }
   if (HaveContexts()) {
     if (context_type != feature_info_->context_type()) {
       DLOG(ERROR) << "ContextGroup::Initialize failed because the type of "