Revert of current program can be null in ES2/ES3 contexts.

gpu/command_buffer/service/vertex_attrib_manager.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.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_VERTEX_ATTRIB_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_VERTEX_ATTRIB_MANAGER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 183 matching lines @@
   }
 
   VertexAttrib* GetVertexAttrib(GLuint index) {
     if (index < vertex_attribs_.size()) {
       return &vertex_attribs_[index];
     }
     return NULL;
   }
 
   void UpdateAttribBaseTypeAndMask(GLuint loc, GLenum base_type) {
-    DCHECK(loc < vertex_attribs_.size());
+    DCHECK(loc < max_vertex_attribs_);
     int shift_bits = (loc % 16) * 2;
     attrib_enabled_mask_[loc / 16] |= (0x3 << shift_bits);
     attrib_base_type_mask_[loc / 16] &= ~(0x3 << shift_bits);
     attrib_base_type_mask_[loc / 16] |= base_type << shift_bits;
   }
 
-  const std::vector<uint32_t>& attrib_base_type_mask() const {
-    return attrib_base_type_mask_;
+  // Return 16 attributes' base types, in which the attribute
+  // specified by argument 'loc' located.
+  uint32_t attrib_base_type_mask(GLuint loc) const {
+    DCHECK(loc < max_vertex_attribs_);
+    return attrib_base_type_mask_[loc / 16];
   }
-  const std::vector<uint32_t>& attrib_enabled_mask() const {
-    return attrib_enabled_mask_;
+
+  // Return 16 attributes' type written masks, in which the
+  // attribute specified by argument 'loc' located.
+  uint32_t attrib_enabled_mask(GLuint loc) const {
+    DCHECK(loc < max_vertex_attribs_);
+    return attrib_enabled_mask_[loc / 16];
   }
 
   void SetAttribInfo(
       GLuint index,
       Buffer* buffer,
       GLint size,
       GLenum type,
       GLboolean normalized,
       GLsizei gl_stride,
       GLsizei real_stride,
@@ skipping 66 matching lines @@
     deleted_ = true;
   }
 
   // number of attribs using type GL_FIXED.
   int num_fixed_attribs_;
 
   // Info for each vertex attribute saved so we can check at glDrawXXX time
   // if it is safe to draw.
   std::vector<VertexAttrib> vertex_attribs_;
 
+  uint32_t max_vertex_attribs_;
   // Vertex attrib base types: FLOAT, INT, or UINT.
   // Each base type is encoded into 2 bits, the lowest 2 bits for location 0,
-  // the highest 2 bits for location (max_vertex_attribs - 1).
+  // the highest 2 bits for location (max_vertex_attribs_ - 1).
   std::vector<uint32_t> attrib_base_type_mask_;
   // Same layout as above, 2 bits per location, 0x03 if a location for an
   // vertex attrib is enabled by enabbleVertexAttribArray, 0x00 if it is
   // disabled by disableVertexAttribArray. Every location is 0x00 by default.
   std::vector<uint32_t> attrib_enabled_mask_;
 
   // The currently bound element array buffer. If this is 0 it is illegal
   // to call glDrawElements.
   scoped_refptr<Buffer> element_array_buffer_;
 
   // Lists for which vertex attribs are enabled, disabled.
   VertexAttribList enabled_vertex_attribs_;
   VertexAttribList disabled_vertex_attribs_;
 
   // The VertexArrayManager that owns this VertexAttribManager
   VertexArrayManager* manager_;
 
   // True if deleted.
   bool deleted_;
 
   // Service side vertex array object id.
   GLuint service_id_;
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_VERTEX_ATTRIB_MANAGER_H_