Enforce WARN_UNUSED_RESULT on NavigateToURLAndExpectNoCommit().

Bug: 425335
Change-Id: I4556bb5b1ef2e58b6599746de13b37af22adf5d1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1830358
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Auto-Submit: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700930}

content/browser/security_exploit_browsertest.cc

@@ -751,7 +751,7 @@ IN_PROC_BROWSER_TEST_F(SecurityExploitBrowserTest,
   RenderProcessHostKillWaiter kill_waiter(frame->GetProcess());
 
   ScopedInterfaceParamsReplacer replacer(shell()->web_contents(), nullptr);
-  NavigateToURLAndExpectNoCommit(shell(), non_same_document_url);
+  EXPECT_TRUE(NavigateToURLAndExpectNoCommit(shell(), non_same_document_url));
   EXPECT_EQ(bad_message::RFH_INTERFACE_PROVIDER_MISSING, kill_waiter.Wait());
 
   // Verify that the death of the renderer process doesn't leave behing and leak

content/public/test/content_browser_test_utils.h

@@ -106,7 +106,8 @@ void NavigateToURLBlockUntilNavigationsComplete(Shell* window,
 // Navigates |window| to |url|, blocks until the navigation finishes, and
 // checks that the navigation did not commit (e.g., due to a crash or
 // download).
-bool NavigateToURLAndExpectNoCommit(Shell* window, const GURL& url);
+WARN_UNUSED_RESULT bool NavigateToURLAndExpectNoCommit(Shell* window,
+                                                       const GURL& url);
 
 // Reloads |window|, blocking until the given number of navigations finishes.
 void ReloadBlockUntilNavigationsComplete(Shell* window,