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

gpu/command_buffer/common/gles2_cmd_utils.cc

Index: gpu/command_buffer/common/gles2_cmd_utils.cc
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.cc b/gpu/command_buffer/common/gles2_cmd_utils.cc
index 098a9eed5965e7255926ac1647bdd165670fea19..a36711defe597a6f3ef5d1778844cf157c3c5ae7 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -1239,7 +1239,7 @@ const int32 kBufferDestroyed = 0x3095;  // EGL_BUFFER_DESTROYED
 const int32 kBindGeneratesResource = 0x10000;
 const int32 kFailIfMajorPerfCaveat = 0x10001;
 const int32 kLoseContextWhenOutOfMemory = 0x10002;
-const int32 kWebGLVersion = 0x10003;
+const int32 kContextType = 0x10003;
 
 }  // namespace
 
@@ -1256,8 +1256,7 @@ ContextCreationAttribHelper::ContextCreationAttribHelper()
       bind_generates_resource(true),
       fail_if_major_perf_caveat(false),
       lose_context_when_out_of_memory(false),
-      webgl_version(0) {
-}
+      context_type(CONTEXT_TYPE_OPENGLES2) {}
 
 void ContextCreationAttribHelper::Serialize(std::vector<int32>* attribs) const {
   if (alpha_size != -1) {
@@ -1300,8 +1299,8 @@ void ContextCreationAttribHelper::Serialize(std::vector<int32>* attribs) const {
   attribs->push_back(fail_if_major_perf_caveat ? 1 : 0);
   attribs->push_back(kLoseContextWhenOutOfMemory);
   attribs->push_back(lose_context_when_out_of_memory ? 1 : 0);
-  attribs->push_back(kWebGLVersion);
-  attribs->push_back(webgl_version);
+  attribs->push_back(kContextType);
+  attribs->push_back(context_type);
   attribs->push_back(kNone);
 }
 
@@ -1356,8 +1355,8 @@ bool ContextCreationAttribHelper::Parse(const std::vector<int32>& attribs) {
       case kLoseContextWhenOutOfMemory:
         lose_context_when_out_of_memory = value != 0;
         break;
-      case kWebGLVersion:
-        webgl_version = value;
+      case kContextType:
+        context_type = static_cast<ContextType>(value);
         break;
       case kNone:
         // Terminate list, even if more attributes.