Refactoring: HashMap: provide a pointer match function, so users don't need to.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 71672d7e4e9c863ce3af8c2ea9337283946cb185..45f55f86e2bc6ee930d0af39e7975797956f73d5 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2179,12 +2179,7 @@ static uint32_t Hash(RegisteredExtension* extension) {
 }
 
 
-static bool MatchRegisteredExtensions(void* key1, void* key2) {
-  return key1 == key2;
-}
-
-Genesis::ExtensionStates::ExtensionStates()
-  : map_(MatchRegisteredExtensions, 8) { }
+Genesis::ExtensionStates::ExtensionStates() : map_(HashMap::PointersMatch, 8) {}
 
 Genesis::ExtensionTraversalState Genesis::ExtensionStates::get_state(
     RegisteredExtension* extension) {