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 84 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 {
+  enum DataType {
+    kFloat,
+    kInt,
+    kUInt,
+  };
+
   Vec4() {
     v[0] = 0.0f;
     v[1] = 0.0f;
     v[2] = 0.0f;
     v[3] = 1.0f;
+    type = kFloat;
   }
+  // Use double type here so when storing data of type GLfloat, GLint,
+  // or GLuint, there will be no data loss.
   float v[4];
+  DataType type;

[Zhenyao Mo, 2015/05/12 23:57:45]

Note that in this CL, we don't hook up the setting of this |type| field with any
of the glVertexAttrib* calls.  This CL limits to the glGetVertexAttrib handling.
 An followup CL will fix such issues.

 };
 
 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_