Add ES3 commands GetVertexAttribI{u}iv to GPU command buffer.

gpu/command_buffer/service/context_state.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains the ContextState class.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_CONTEXT_STATE_H_
 #define GPU_COMMAND_BUFFER_SERVICE_CONTEXT_STATE_H_
 
 #include <vector>
@@ skipping 83 matching lines @@
     }
     if (bound_texture_3d.get() == texture) {
       bound_texture_3d = NULL;
     }
     if (bound_texture_2d_array.get() == texture) {
       bound_texture_2d_array = NULL;
     }
   }
 };
 
-struct Vec4 {
+class GPU_EXPORT Vec4 {
+ public:
+  enum DataType {
+    kFloat,
+    kInt,
+    kUInt,
+  };
+
   Vec4() {
-    v[0] = 0.0f;
-    v[1] = 0.0f;
-    v[2] = 0.0f;
-    v[3] = 1.0f;
+    v_[0].float_value = 0.0f;
+    v_[1].float_value = 0.0f;
+    v_[2].float_value = 0.0f;
+    v_[3].float_value = 1.0f;
+    type_ = kFloat;
   }
-  float v[4];
+
+  void GetValues(GLfloat* values) const;

[piman, 2015/05/13 19:33:27]

nit: we typically disallow overloading per style guide.

How about GetFloats/GetInts/GetUInts and SetFloats/SetInts/SetUInts?

Or templates are fine too, you just need to make sure the specializations are
exported.

+  void GetValues(GLint* values) const;
+  void GetValues(GLuint* values) const;
+
+  void SetValues(const GLfloat* values);
+  void SetValues(const GLint* values);
+  void SetValues(const GLuint* values);
+
+  DataType type() const {
+    return type_;
+  }
+
+  bool Equal(const Vec4& other) const;
+
+ private:
+  union ValueUnion {
+    GLfloat float_value;
+    GLint int_value;
+    GLuint uint_value;
+  };
+
+  ValueUnion v_[4];
+  DataType type_;
 };
 
 struct GPU_EXPORT ContextState {
   ContextState(FeatureInfo* feature_info,
                ErrorStateClient* error_state_client,
                Logger* logger);
   ~ContextState();
 
   void Initialize();
 
@@ skipping 113 matching lines @@
 
   FeatureInfo* feature_info_;
   scoped_ptr<ErrorState> error_state_;
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_CONTEXT_STATE_H_