Removed use of RefPtr::Release where result is not used.

third_party/WebKit/Source/platform/wtf/RefPtr.h

Index: third_party/WebKit/Source/platform/wtf/RefPtr.h
diff --git a/third_party/WebKit/Source/platform/wtf/RefPtr.h b/third_party/WebKit/Source/platform/wtf/RefPtr.h
index aa369a0e0eeff3463abc7d69e9e52bae2b84063e..b4b81137f3a06f6a6485d4c9bba431b28075d84f 100644
--- a/third_party/WebKit/Source/platform/wtf/RefPtr.h
+++ b/third_party/WebKit/Source/platform/wtf/RefPtr.h
@@ -70,7 +70,7 @@ class RefPtr {
   ALWAYS_INLINE T* Get() const { return ptr_; }
   T* LeakRef() WARN_UNUSED_RESULT;
   void Clear();
-  PassRefPtr<T> Release() {
+  PassRefPtr<T> Release() WARN_UNUSED_RESULT {
     PassRefPtr<T> tmp = AdoptRef(ptr_);
     ptr_ = nullptr;
     return tmp;