[Aura] Use GLHelper support to validate format before processing texture

content/common/gpu/client/gl_helper_readback_support.cc

 // Copyright 2014 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 "content/common/gpu/client/gl_helper_readback_support.h"
 #include "base/logging.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "third_party/skia/include/core/SkImageInfo.h"
 
 namespace content {
 
 GLHelperReadbackSupport::GLHelperReadbackSupport(gpu::gles2::GLES2Interface* gl)
     : gl_(gl) {
   InitializeReadbackSupport();
 }
 
 GLHelperReadbackSupport::~GLHelperReadbackSupport() {}
 
 void GLHelperReadbackSupport::InitializeReadbackSupport() {
   // We are concerned about 16, 32-bit formats only.  The below are the most
   // used 16, 32-bit formats.  In future if any new format support is needed
   // that should be added here.  Initialize the array with
   // GLHelperReadbackSupport::NOT_SUPPORTED as we dont know the supported
   // formats yet.
   for (int i = 0; i <= kLastEnum_SkColorType; ++i) {
     format_support_table_[i] = GLHelperReadbackSupport::NOT_SUPPORTED;
   }
+  // TODO(sikugu): kAlpha_8_SkColorType support check is failing on mesa.
+  // See crbug.com/415667.
   CheckForReadbackSupport(kRGB_565_SkColorType);
   CheckForReadbackSupport(kARGB_4444_SkColorType);
   CheckForReadbackSupport(kRGBA_8888_SkColorType);
   CheckForReadbackSupport(kBGRA_8888_SkColorType);
   // Further any formats, support should be checked here.
 }
 
 void GLHelperReadbackSupport::CheckForReadbackSupport(
     SkColorType texture_format) {
   bool supports_format = false;
@@ skipping 132 matching lines @@
       return GLHelperReadbackSupport::NOT_SUPPORTED;
     default:
       NOTREACHED();
       break;
   }
 
   return GLHelperReadbackSupport::NOT_SUPPORTED;
 }
 
 }  // namespace content