Remove user-defined move constructor and assignment operator from WTF::String

Source/wtf/text/WTFString.h

Index: Source/wtf/text/WTFString.h
diff --git a/Source/wtf/text/WTFString.h b/Source/wtf/text/WTFString.h
index 13078127885b7c8233cbb1e20515fdbd60125df8..c7650b50e9096329045deedd181dc733ef0e363d 100644
--- a/Source/wtf/text/WTFString.h
+++ b/Source/wtf/text/WTFString.h
@@ -123,15 +123,6 @@ public:
     String(StringImpl* impl) : m_impl(impl) { }
     String(PassRefPtr<StringImpl> impl) : m_impl(impl) { }
 
-#if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
-    // We have to declare the copy constructor and copy assignment operator as well, otherwise
-    // they'll be implicitly deleted by adding the move constructor and move assignment operator.
-    String(const String& other) : m_impl(other.m_impl) { }
-    String(String&& other) : m_impl(other.m_impl.release()) { }
-    String& operator=(const String& other) { m_impl = other.m_impl; return *this; }
-    String& operator=(String&& other) { m_impl = other.m_impl.release(); return *this; }

[Inactive, 2014/07/21 11:15:43]

Mikhail, are you sure about this? I thought the move constructor was not
generated here because of the user defined destructor. 

[Mikhail, 2014/07/21 12:35:44]

Thanks for catching this, Chris! The thing is that WTF::String does not need to
have user-defined destructor, I should have removed it here. I'll remove it with
the following CL.

-#endif
-
     // Inline the destructor.
     ALWAYS_INLINE ~String() { }