Update v8 to version 2.5.5.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/4685001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@65374 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -58,7 +58,7 @@ deps = {
     (Var("googlecode_url") % "gyp") + "/trunk@856",
 
   "src/v8":
-    (Var("googlecode_url") % "v8") + "/trunk@5757",
+    (Var("googlecode_url") % "v8") + "/trunk@5780",
 
   "src/native_client":
     Var("nacl_trunk") + "/src/native_client@" + Var("nacl_revision"),