Improve the run time of base_unittests by about 20s by reducing timeouts in

base/observer_list_unittest.cc

Index: base/observer_list_unittest.cc
diff --git a/base/observer_list_unittest.cc b/base/observer_list_unittest.cc
index 332de367f736df351877d124a49b1fda40895ea6..ba4b5de04bbcfc9d2a752a94fe33f3f6005fa4e1 100644
--- a/base/observer_list_unittest.cc
+++ b/base/observer_list_unittest.cc
@@ -83,7 +83,7 @@ class AddInObserve : public Foo {
 class ObserverListThreadSafeTest : public testing::Test {
 };
 
-static const int kThreadRunTime = 10000;  // ms to run the multi-threaded test.
+static const int kThreadRunTime = 2000;  // ms to run the multi-threaded test.
 
 // A thread for use in the ThreadSafeObserver test
 // which will add and remove itself from the notification