Allow explicit conversion operators and implement WTF::OwnPtr::operator bool.

third_party/WebKit/Source/wtf/OwnPtr.h

Index: third_party/WebKit/Source/wtf/OwnPtr.h
diff --git a/third_party/WebKit/Source/wtf/OwnPtr.h b/third_party/WebKit/Source/wtf/OwnPtr.h
index 0b0b58e081883b6b114a5ab04d6c8a17cf6d1f28..391031ca4c7d93c088c901d09990ba9f88cbaf18 100644
--- a/third_party/WebKit/Source/wtf/OwnPtr.h
+++ b/third_party/WebKit/Source/wtf/OwnPtr.h
@@ -70,11 +70,7 @@ public:
     ValueType& operator[](std::ptrdiff_t i) const;
 
     bool operator!() const { return !m_ptr; }
-
-    // This conversion operator allows implicit conversion to bool but not to
-    // other integer types.
-    typedef PtrType OwnPtr::*UnspecifiedBoolType;
-    operator UnspecifiedBoolType() const { return m_ptr ? &OwnPtr::m_ptr : 0; }
+    explicit operator bool() const { return m_ptr; }

[danakj, 2016/04/12 23:23:24]

do you mean return !!m_ptr?

not sure if this leaks the pointer and people could cast it from bool to pointer
again or weird things?

[jbroman, 2016/04/12 23:26:38]

No, conversion to bool will result in either |true| or |false|.
http://en.cppreference.com/w/cpp/language/implicit_conversion#Boolean_convers...

[danakj, 2016/04/12 23:30:11]

Yay thanks

 
     OwnPtr& operator=(const PassOwnPtr<T>&);
     OwnPtr& operator=(std::nullptr_t) { clear(); return *this; }