Don't leak CopyResult textures.

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 412a55d968d13270ac55917a03e3b7f60339b195..55213cde6b86a6c56e09061e85e65a50b4dea35c 100644
--- a/cc/output/copy_output_result.cc
+++ b/cc/output/copy_output_result.cc
@@ -26,7 +26,10 @@ CopyOutputResult::CopyOutputResult(gfx::Size size,
   DCHECK(texture_mailbox_->IsTexture());
 }
 
-CopyOutputResult::~CopyOutputResult() {}
+CopyOutputResult::~CopyOutputResult() {
+  if (texture_mailbox_)
+    texture_mailbox_->RunReleaseCallback(0, false);
+}
 
 scoped_ptr<SkBitmap> CopyOutputResult::TakeBitmap() {
   return bitmap_.Pass();