Fix some grammar in chrome/browser/resources/

chrome/browser/net/sqlite_persistent_cookie_store_perftest.cc

Index: chrome/browser/net/sqlite_persistent_cookie_store_perftest.cc
diff --git a/chrome/browser/net/sqlite_persistent_cookie_store_perftest.cc b/chrome/browser/net/sqlite_persistent_cookie_store_perftest.cc
index b3e7d4af7af74cc38e5e2cce496e3e434f103393..4d97b81e3cec5670eac65927f55a26c668ae5664 100644
--- a/chrome/browser/net/sqlite_persistent_cookie_store_perftest.cc
+++ b/chrome/browser/net/sqlite_persistent_cookie_store_perftest.cc
@@ -68,7 +68,7 @@ class SQLitePersistentCookieStorePerfTest : public testing::Test {
       }
     }
     // Replace the store effectively destroying the current one and forcing it
-    // to write it's data to disk.
+    // to write its data to disk.
     store_ = NULL;
     scoped_refptr<base::ThreadTestHelper> helper(
       new base::ThreadTestHelper(