Allow premultiply_alpha + unpremultiply_alpha in CopyTextureCHROMIUMResourceManager

gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.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/gles2_cmd_copy_texture_chromium.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 19 matching lines @@
   FRAGMENT_SHADER_COPY_TEXTURE_UNPREMULTIPLY_ALPHA_RECTANGLE_ARB,
   FRAGMENT_SHADER_COPY_TEXTURE_UNPREMULTIPLY_ALPHA_EXTERNAL_OES,
   NUM_FRAGMENT_SHADERS,
 };
 
 // Returns the correct fragment shader id to evaluate the copy operation for
 // the premultiply alpha pixel store settings and target.
 FragmentShaderId GetFragmentShaderId(bool premultiply_alpha,
                                      bool unpremultiply_alpha,
                                      GLenum target) {
-  // Only one alpha mode at a time makes sense.
-  DCHECK(!premultiply_alpha || !unpremultiply_alpha);
-
   enum {
     SAMPLER_2D,
     SAMPLER_RECTANGLE_ARB,
     SAMPLER_EXTERNAL_OES,
     NUM_SAMPLERS
   };
 
   // bit 0: premultiply alpha
   // bit 1: unpremultiply alpha
   static FragmentShaderId shader_ids[][NUM_SAMPLERS] = {
@@ skipping 76 matching lines @@
                          u_vertex_dest_add;\n\
         v_uv = a_position.xy * u_vertex_source_mult + u_vertex_source_add;\n\
       }\n");
 
   return source;
 }
 
 std::string GetFragmentShaderSource(bool premultiply_alpha,
                                     bool unpremultiply_alpha,
                                     GLenum target) {
-  // Only one alpha mode at a time makes sense.
-  DCHECK(!premultiply_alpha || !unpremultiply_alpha);
-
   std::string source;
 
   // Preamble for core and compatibility mode.
   if (gl::GetGLImplementation() == gl::kGLImplementationDesktopGLCoreProfile) {
     source += std::string("\
         #version 150\n\
         out vec4 frag_color;\n\
         #define VARYING in\n\
         #define FRAGCOLOR frag_color\n\
         #define TextureLookup texture\n");
@@ skipping 603 matching lines @@
   decoder->RestoreTextureState(dest_id);
   decoder->RestoreTextureUnitBindings(0);
   decoder->RestoreActiveTexture();
   decoder->RestoreProgramBindings();
   decoder->RestoreBufferBindings();
   decoder->RestoreFramebufferBindings();
   decoder->RestoreGlobalState();
 }
 
 }  // namespace gpu