Switch adb over to <chrono>.

Clearer code, and lets us lose some more portability cruft.

Bug: http://b/32878766
Test: manual
Change-Id: Ie44928bbf8d68a74127aaf76e7e0060e25fa2cc8
diff --git a/adb/usb_osx.cpp b/adb/usb_osx.cpp
index 2ee2aae..e541f6e 100644
--- a/adb/usb_osx.cpp
+++ b/adb/usb_osx.cpp
@@ -30,8 +30,10 @@
 #include <stdio.h>
 
 #include <atomic>
+#include <chrono>
 #include <memory>
 #include <mutex>
+#include <thread>
 #include <vector>
 
 #include <android-base/logging.h>
@@ -40,6 +42,8 @@
 #include "adb.h"
 #include "transport.h"
 
+using namespace std::chrono_literals;
+
 struct usb_handle
 {
     UInt8 bulkIn;
@@ -411,7 +415,7 @@
         }
         // Signal the parent that we are running
         usb_inited_flag = true;
-        adb_sleep_ms(1000);
+        std::this_thread::sleep_for(1s);
     }
     VLOG(USB) << "RunLoopThread done";
 }
@@ -436,7 +440,7 @@
 
         // Wait for initialization to finish
         while (!usb_inited_flag) {
-            adb_sleep_ms(100);
+            std::this_thread::sleep_for(100ms);
         }
 
         initialized = true;