Added Chrome-side support for EXT_blend_minmax WebGL extension

gpu/command_buffer/service/feature_info.cc

 // 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.
 
 #include "gpu/command_buffer/service/feature_info.h"
 
 #include <set>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 759 matching lines @@
     validators_.g_l_state.AddValue(GL_MAX_DRAW_BUFFERS_ARB);
     GLint max_draw_buffers = 0;
     glGetIntegerv(GL_MAX_DRAW_BUFFERS_ARB, &max_draw_buffers);
     for (GLenum i = GL_DRAW_BUFFER0_ARB;
          i < static_cast<GLenum>(GL_DRAW_BUFFER0_ARB + max_draw_buffers);
          ++i) {
       validators_.g_l_state.AddValue(i);
     }
   }
 
+  if (extensions.Contains("GL_EXT_blend_minmax") ||
+      gfx::HasDesktopGLFeatures()) {
+    AddExtensionString("GL_EXT_blend_minmax");
+    validators_.equation.AddValue(GL_MIN_EXT);
+    validators_.equation.AddValue(GL_MAX_EXT);
+  }
+
   if (extensions.Contains("GL_EXT_frag_depth") || gfx::HasDesktopGLFeatures()) {
     AddExtensionString("GL_EXT_frag_depth");
     feature_flags_.ext_frag_depth = true;
   }
 
   if (extensions.Contains("GL_EXT_shader_texture_lod") ||
       gfx::HasDesktopGLFeatures()) {
     AddExtensionString("GL_EXT_shader_texture_lod");
     feature_flags_.ext_shader_texture_lod = true;
   }
@@ skipping 47 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu