command_buffer: Add support for creating non-WebGL ES 3 contexts

gpu/command_buffer/common/gles2_cmd_utils.h

Index: gpu/command_buffer/common/gles2_cmd_utils.h
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.h b/gpu/command_buffer/common/gles2_cmd_utils.h
index 806b297326f2584689c005b0fea476621d692fad..b29f96b4fa51f912c5ef5dbe890d37e7175e3c29 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.h
+++ b/gpu/command_buffer/common/gles2_cmd_utils.h
@@ -204,6 +204,13 @@ class GLES2_UTILS_EXPORT GLES2Util {
   int num_shader_binary_formats_;
 };
 
+enum ContextType {
+  CONTEXT_TYPE_WEBGL1,
+  CONTEXT_TYPE_WEBGL2,
+  CONTEXT_TYPE_OPENGLES2,
+  CONTEXT_TYPE_OPENGLES3
+};
+
 struct GLES2_UTILS_EXPORT ContextCreationAttribHelper {
   ContextCreationAttribHelper();
 
@@ -223,8 +230,7 @@ struct GLES2_UTILS_EXPORT ContextCreationAttribHelper {
   bool bind_generates_resource;
   bool fail_if_major_perf_caveat;
   bool lose_context_when_out_of_memory;
-  // 0 if not a WebGL context.
-  unsigned webgl_version;
+  ContextType context_type;
 };
 
 }  // namespace gles2