Query the preferred readback config in CopyFromBackingStore

content/common/gpu/client/gl_helper_readback_support.cc

Index: content/common/gpu/client/gl_helper_readback_support.cc
diff --git a/content/common/gpu/client/gl_helper_readback_support.cc b/content/common/gpu/client/gl_helper_readback_support.cc
index 28bae135670a8e9886e44cbcf2454a607714b261..d3e31eda89927ac96a6d0772256e21233f4a1291 100644
--- a/content/common/gpu/client/gl_helper_readback_support.cc
+++ b/content/common/gpu/client/gl_helper_readback_support.cc
@@ -4,6 +4,9 @@
 
 #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 {
 
@@ -90,4 +93,17 @@ bool GLHelperReadbackSupport::IsReadbackConfigSupported(
   }
 }
 
+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