Move StringView constructors into WTFString.h/AtomicString.h

third_party/WebKit/Source/wtf/text/WTFString.h

Index: third_party/WebKit/Source/wtf/text/WTFString.h
diff --git a/third_party/WebKit/Source/wtf/text/WTFString.h b/third_party/WebKit/Source/wtf/text/WTFString.h
index 839454d9a9617bcb2d07f052cd6f3bfe88534bf4..86f6e6bfae8ebd3eb6f36d25d237667142f2bc2a 100644
--- a/third_party/WebKit/Source/wtf/text/WTFString.h
+++ b/third_party/WebKit/Source/wtf/text/WTFString.h
@@ -30,6 +30,7 @@
 #include "wtf/WTFExport.h"
 #include "wtf/text/ASCIIFastPath.h"
 #include "wtf/text/StringImpl.h"
+#include "wtf/text/StringView.h"
 #include <algorithm>
 #include <iosfwd>
 
@@ -639,6 +640,13 @@ WTF_EXPORT extern const String& xmlnsWithColon;
 // double-quotes, and escapes chracters other than ASCII printables.
 WTF_EXPORT std::ostream& operator<<(std::ostream&, const String&);
 
+inline StringView::StringView(const String& string, unsigned offset, unsigned length)
+    : StringView(string.impl(), offset, length) {}
+inline StringView::StringView(const String& string, unsigned offset)
+    : StringView(string.impl(), offset) {}
+inline StringView::StringView(const String& string)
+    : StringView(string.impl()) {}
+
 } // namespace WTF
 
 WTF_ALLOW_MOVE_AND_INIT_WITH_MEM_FUNCTIONS(String);