Move Time, TimeDelta and TimeTicks into namespace base.

Review URL: http://codereview.chromium.org/7995

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@4022 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/perftimer.h b/base/perftimer.h
index 86314e9..9558697 100644
--- a/base/perftimer.h
+++ b/base/perftimer.h
@@ -31,16 +31,16 @@
 class PerfTimer {
  public:
   PerfTimer() {
-    begin_ = TimeTicks::Now();
+    begin_ = base::TimeTicks::Now();
   }
 
   // Returns the time elapsed since object construction
-  TimeDelta Elapsed() const {
-    return TimeTicks::Now() - begin_;
+  base::TimeDelta Elapsed() const {
+    return base::TimeTicks::Now() - begin_;
   }
 
  private:
-  TimeTicks begin_;
+  base::TimeTicks begin_;
 };
 
 // ----------------------------------------------------------------------