Implemented StructTraits for cc::CopyOutputResult

cc/output/copy_output_result.cc

Index: cc/output/copy_output_result.cc
diff --git a/cc/output/copy_output_result.cc b/cc/output/copy_output_result.cc
index 3a349f27fb8d3aeffb17726f9a7ad46035b2c4d8..5560bb517d11cc03358cf0e5194c353e1f33b075 100644
--- a/cc/output/copy_output_result.cc
+++ b/cc/output/copy_output_result.cc
@@ -6,7 +6,6 @@
 
 #include "base/logging.h"
 #include "cc/resources/texture_mailbox.h"
-#include "third_party/skia/include/core/SkBitmap.h"
 
 namespace cc {
 
@@ -32,6 +31,9 @@ CopyOutputResult::~CopyOutputResult() {
     release_callback_->Run(gpu::SyncToken(), false);
 }
 
+CopyOutputResult& CopyOutputResult::operator=(CopyOutputResult&& other) =
+    default;
+
 std::unique_ptr<SkBitmap> CopyOutputResult::TakeBitmap() {
   return std::move(bitmap_);
 }