Query the preferred readback config in CopyFromBackingStore

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"
+#if defined(OS_ANDROID)
+#include "base/android/sys_utils.h"
+#endif
 
 namespace content {
 
 GLHelperReadbackSupport::GLHelperReadbackSupport(gpu::gles2::GLES2Interface* gl)
     : gl_(gl) {
   InitializeReadbackSupport();
 }
 
 GLHelperReadbackSupport::~GLHelperReadbackSupport() {}
 
@@ skipping 66 matching lines @@
     case FORMAT_SUPPORTED:
       return true;
     case FORMAT_NOT_SUPPORTED:
       return false;
     default:
       NOTREACHED();
       return false;
   }
 }
 
+SkBitmap::Config GLHelperReadbackSupport::PreferredReadbackFormat() {
+#if defined(OS_ANDROID)
+  // Define the criteria here. If say the 16 texture readbback is
+  // supported we should go with that (this degrades quality)
+  // or stick back to the default format.
+  if (base::android::SysUtils::IsLowEndDevice()) {
+    if (IsReadbackConfigSupported(SkBitmap::kRGB_565_Config))
+      return SkBitmap::kRGB_565_Config;
+  }
+#endif
+  return SkBitmap::kARGB_8888_Config;
+}
+
 }  // namespace content