Reduce number of iterations on TimeTicks.Deltas test
so that unittests run faster.

BUG=22061
TEST=this is the test

Review URL: http://codereview.chromium.org/462010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33631 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/time_unittest.cc b/base/time_unittest.cc
index f8a62cb..81daab0 100644
--- a/base/time_unittest.cc
+++ b/base/time_unittest.cc
@@ -91,7 +91,7 @@
 }
 
 TEST(TimeTicks, Deltas) {
-  for (int index = 0; index < 500; index++) {
+  for (int index = 0; index < 50; index++) {
     TimeTicks ticks_start = TimeTicks::Now();
     PlatformThread::Sleep(10);
     TimeTicks ticks_stop = TimeTicks::Now();