Convert use of int ms to TimeDelta in files owned by brettw.

chrome/common/worker_thread_ticker.h

Index: chrome/common/worker_thread_ticker.h
diff --git a/chrome/common/worker_thread_ticker.h b/chrome/common/worker_thread_ticker.h
index dc5f542a5b69e1ee0ef49a91eae0db4ca1a05135..99449c36c116e5fb990173461e62b282859919dd 100644
--- a/chrome/common/worker_thread_ticker.h
+++ b/chrome/common/worker_thread_ticker.h
@@ -58,11 +58,11 @@ class WorkerThreadTicker {
   }
 
   void set_tick_interval(int tick_interval) {
-    tick_interval_ = tick_interval;
+    tick_interval_ = base::TimeDelta::FromMilliseconds(tick_interval);
   }
 
   int tick_interval() const {
-    return tick_interval_;
+    return tick_interval_.InMilliseconds();
   }
 
  private:
@@ -80,7 +80,7 @@ class WorkerThreadTicker {
   bool is_running_;
 
   // The interval at which the callbacks are to be invoked
-  int tick_interval_;
+  base::TimeDelta tick_interval_;
 
   // A list that holds all registered callback interfaces
   TickHandlerListType tick_handler_list_;