Add toStdString methods to CString and WTF::String

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 256abc6a131a9904461570997cf74da03650d099..d2045f8b6dab1fe1ff31262c886ec403d037c451 100644
--- a/third_party/WebKit/Source/wtf/text/WTFString.h
+++ b/third_party/WebKit/Source/wtf/text/WTFString.h
@@ -33,6 +33,7 @@
 #include "wtf/text/StringView.h"
 #include <algorithm>
 #include <iosfwd>
+#include <string>
 
 #ifdef __OBJC__
 #include <objc/objc.h>
@@ -179,6 +180,10 @@ public:
     CString latin1() const;
     CString utf8(UTF8ConversionMode = LenientUTF8Conversion) const;
 
+    // This method should be used ONLY to pass a WTFString to methods outside
+    // of blink which take a std::string as an argument.
+    std::string toUTF8StdString() const;
+
     UChar operator[](unsigned index) const
     {
         if (!m_impl || index >= m_impl->length())