Add move constructors and assignment operators to GURL

url/gurl.h

Index: url/gurl.h
diff --git a/url/gurl.h b/url/gurl.h
index ae2c40889f9aa6526307d17cad164c247ad547f1..4cbd84656f989a63ff54ccf50fa3b3aa484c658c 100644
--- a/url/gurl.h
+++ b/url/gurl.h
@@ -54,6 +54,7 @@ class URL_EXPORT GURL {
   // Copy construction is relatively inexpensive, with most of the time going
   // to reallocating the string. It does not re-parse.
   GURL(const GURL& other);
+  GURL(GURL&& other);
 
   // The strings to this contructor should be UTF-8 / UTF-16.
   explicit GURL(base::StringPiece url_string);
@@ -76,7 +77,8 @@ class URL_EXPORT GURL {
 
   ~GURL();
 
-  GURL& operator=(GURL other);
+  GURL& operator=(const GURL& other);
+  GURL& operator=(GURL&& other);
 
   // Returns true when this object represents a valid parsed URL. When not
   // valid, other functions will still succeed, but you will not get canonical