[chromedriver] Improve timeout behavior. Prompted by user who executes script on busy page.

chrome/test/chromedriver/chrome/devtools_client.h

Index: chrome/test/chromedriver/chrome/devtools_client.h
diff --git a/chrome/test/chromedriver/chrome/devtools_client.h b/chrome/test/chromedriver/chrome/devtools_client.h
index db79210eb565ab6900d015f15a61f2907ef6e2dc..05f5dfc54407aad9e757c502b556eb7c6d67da51 100644
--- a/chrome/test/chromedriver/chrome/devtools_client.h
+++ b/chrome/test/chromedriver/chrome/devtools_client.h
@@ -43,8 +43,8 @@ class DevToolsClient {
   // Handles events until the given function reports the condition is met
   // and there are no more received events to handle. If the given
   // function ever returns an error, returns immediately with the error.
-  // If the condition is not met within |timeout|ms, kTimeout status
-  // is returned eventually.
+  // If the condition is not met within |timeout|, kTimeout status
+  // is returned eventually. If |timeout| is 0, this function will not block.
   virtual Status HandleEventsUntil(const ConditionalFunc& conditional_func,
                                    const base::TimeDelta& timeout) = 0;