Reland of Disable flaky WebNavigationApiTest.CrossProcessHistory. (patchset #1...

Reland of Disable flaky WebNavigationApiTest.CrossProcessHistory. (patchset #1 id:1 of https://codereview.chromium.org/2830813002/ )

Reason for revert:
The flakiness came back upon landing this revert.

So, reverting the revert.

Original issue's description:
> Revert of Disable flaky WebNavigationApiTest.CrossProcessHistory. (patchset #1 id:1 of https://codereview.chromium.org/2790383002/ )
>
> Reason for revert:
> What I believe was the underlying issue has been reverted, so it should be safe to reenable this test back.
>
> Original issue's description:
> > Disable flaky WebNavigationApiTest.CrossProcessHistory.
> >
> > TBR=nasko@chromium.org
> > BUG=708139
> >
> > Review-Url: https://codereview.chromium.org/2790383002
> > Cr-Commit-Position: refs/heads/master@{#461690}
> > Committed: https://chromium.googlesource.com/chromium/src/+/656fccff69eae8da012f0f83bcd3fc89214c5258
>
> TBR=maxmorin@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=708139
>
> Review-Url: https://codereview.chromium.org/2830813002
> Cr-Commit-Position: refs/heads/master@{#465709}
> Committed: https://chromium.googlesource.com/chromium/src/+/ccdcc6ef79a614b1b1c87a78a883d9c5b19ffde2

TBR=maxmorin@chromium.org,nasko@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=708139

Review-Url: https://codereview.chromium.org/2828903002
Cr-Commit-Position: refs/heads/master@{#465748}

chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc

@@ -747,7 +747,8 @@ IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, DISABLED_CrossProcessFragment) {
       << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, CrossProcessHistory) {
+// crbug.com/708139.
+IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, DISABLED_CrossProcessHistory) {
   ASSERT_TRUE(StartEmbeddedTestServer());
 
   // See crossProcessHistory/e.html.