Add a WebDocument::watchCssSelectors(selectors)

public/platform/WebCString.h

Index: public/platform/WebCString.h
diff --git a/public/platform/WebCString.h b/public/platform/WebCString.h
index 81e2065fd347c9e03f2599f119bc667f07a4d22a..f380695f21c809a0b96e4e8c167264bec0d6330f 100644
--- a/public/platform/WebCString.h
+++ b/public/platform/WebCString.h
@@ -36,10 +36,10 @@
 
 #if INSIDE_WEBKIT
 #include <wtf/Forward.h>
-#else
-#include <string>
 #endif
 
+#include <string>
+
 namespace WTF {
 class CString;
 class CStringBuffer;
@@ -106,12 +106,6 @@ public:
         return *this;
     }
 
-    operator std::string() const
-    {
-        size_t len = length();
-        return len ? std::string(data(), len) : std::string();
-    }
-
     template <class UTF16String>
     static WebCString fromUTF16(const UTF16String& s)
     {
@@ -119,6 +113,12 @@ public:
     }
 #endif
 
+    operator std::string() const
+    {
+        size_t len = length();
+        return len ? std::string(data(), len) : std::string();
+    }
+
 private:
     BLINK_COMMON_EXPORT void assign(WTF::CStringBuffer*);
     WebPrivatePtr<WTF::CStringBuffer> m_private;