Refactor: Flip condition in CallbackHelper

Flipping the condition to refer to exception thrown by its branch
makes the method more readable.

Bug: None
Change-Id: I7b7d0bff7f9a43cc2664ee0f31d5a25767439ec2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2414035Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Victor Vianna <victorvianna@google.com>
Cr-Commit-Position: refs/heads/master@{#807440}

base/test/android/javatests/src/org/chromium/base/test/util/CallbackHelper.java

@@ -190,7 +190,7 @@ public class CallbackHelper {
                     Assert.fail(s);
                 }
             }
-            if (callCountWhenDoneWaiting > mCallCount) {
+            if (timer.isTimedOut()) {
                 throw new TimeoutException(msg == null ? "waitForCallback timed out!" : msg);
             }
         }