Add removeAll method to sets and maps and use them

Source/wtf/text/TextEncodingRegistry.cpp

Index: Source/wtf/text/TextEncodingRegistry.cpp
diff --git a/Source/wtf/text/TextEncodingRegistry.cpp b/Source/wtf/text/TextEncodingRegistry.cpp
index 4dd0240043c598532f930409e545dd1a3848e671..7f241343fc7c841ff2f7e3611a93822967d23941 100644
--- a/Source/wtf/text/TextEncodingRegistry.cpp
+++ b/Source/wtf/text/TextEncodingRegistry.cpp
@@ -192,9 +192,7 @@ static void pruneBlacklistedCodecs()
                 names.append(it->key);
         }
 
-        size_t length = names.size();
-        for (size_t j = 0; j < length; ++j)
-            textEncodingNameMap->remove(names[j]);
+        textEncodingNameMap->removeAll(names);
 
         textCodecMap->remove(atomicName);
     }