Replace Increment/DecrementKeepAliveCount by ScopedKeepAlives

chrome/browser/devtools/devtools_sanity_browsertest.cc

Index: chrome/browser/devtools/devtools_sanity_browsertest.cc
diff --git a/chrome/browser/devtools/devtools_sanity_browsertest.cc b/chrome/browser/devtools/devtools_sanity_browsertest.cc
index 62b3284bce8931490d4e61dc68e21ab6eb4a1116..2613d684f3773d15e91d2251abbd2152cc64ca04 100644
--- a/chrome/browser/devtools/devtools_sanity_browsertest.cc
+++ b/chrome/browser/devtools/devtools_sanity_browsertest.cc
@@ -771,7 +771,6 @@ IN_PROC_BROWSER_TEST_F(DevToolsBeforeUnloadTest,
     content::WindowedNotificationObserver close_observer(
         chrome::NOTIFICATION_BROWSER_CLOSED,
         content::Source<Browser>(browser()));
-    chrome::IncrementKeepAliveCount();

[sky, 2016/03/10 04:18:20]

Why is this no longer necessary?

[dgn, 2016/03/10 18:31:51]

That was added to unflake the test a long time ago.
(crbug.com/333554, 323847). I can't find which call it's supposed to pair with.
We currently didn't do anything when the count is in excess, so it might be
superfluous now. I'll investigate some more if I see some new flakes.

     chrome::CloseAllBrowsers();
     AcceptModalDialog();
     AcceptModalDialog();