Reland: WTF: Simplify RefPtr::operator bool.

third_party/WebKit/Source/wtf/PassRefPtr.h

Index: third_party/WebKit/Source/wtf/PassRefPtr.h
diff --git a/third_party/WebKit/Source/wtf/PassRefPtr.h b/third_party/WebKit/Source/wtf/PassRefPtr.h
index 48538cd788a66d22bbbe934ef426f31801288f61..53aad9276218dda2c6fe0a8f014312108d0dd434 100644
--- a/third_party/WebKit/Source/wtf/PassRefPtr.h
+++ b/third_party/WebKit/Source/wtf/PassRefPtr.h
@@ -82,10 +82,7 @@ public:
     T* operator->() const { return m_ptr; }
 
     bool operator!() const { return !m_ptr; }
-
-    // TODO(jbroman): Simplifying this in the obvious way causes a massive
-    // regression in a perf test on ARM. http://crbug.com/607208
-    explicit operator bool() const { return m_ptr ? &PassRefPtr::m_ptr : 0; }
+    explicit operator bool() const { return m_ptr != nullptr; }
 
     friend PassRefPtr adoptRef<T>(T*);