Make TimeoutRetryThread's stoppable

build/android/pylib/utils/watchdog_timer.py

Index: build/android/pylib/utils/watchdog_timer.py
diff --git a/build/android/pylib/utils/watchdog_timer.py b/build/android/pylib/utils/watchdog_timer.py
index d14dabb4dd7800eb1883fc7aae8cdc2b8f4a538f..2f4c46455be7c9751e9a570a8f41cac0e3430cf7 100644
--- a/build/android/pylib/utils/watchdog_timer.py
+++ b/build/android/pylib/utils/watchdog_timer.py
@@ -26,12 +26,22 @@ class WatchdogTimer(object):
     """Resets the timeout countdown."""
     self._start_time = time.time()
 
+  def GetElapsed(self):
+    """Returns the elapsed time of the watchdog."""
+    return time.time() - self._start_time
+
+  def GetRemaining(self):
+    """Returns the remaining time of the watchdog."""
+    if self._timeout:
+      return self._timeout - self.GetElapsed()
+    else:
+      return None
+
   def IsTimedOut(self):
     """Whether the watchdog has timed out.
 
     Returns:
       True if the watchdog has timed out, False otherwise.
     """
-    if self._timeout is None:
-      return False
-    return time.time() - self._start_time > self._timeout
+    remaining = self.GetRemaining()
+    return remaining is not None and remaining < 0