Remove unintended user activation in OpenerNavigation_DownloadPolicy

This fixes the test for UAv2.

Bug: 906639
Change-Id: Ic23f0384691b4cbc3936efabafa2c8cbd128c780
Reviewed-on: https://chromium-review.googlesource.com/c/1342773Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Commit-Queue: Mustaq Ahmed <mustaq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609417}

content/browser/navigation_browsertest.cc

@@ -1435,12 +1435,13 @@ IN_PROC_BROWSER_TEST_F(NavigationBrowserTest, OpenerNavigation_DownloadPolicy) {
   DownloadTestObserverInProgress observer(
       BrowserContext::GetDownloadManager(opener->GetBrowserContext()),
       1 /* wait_count */);
-  EXPECT_TRUE(ExecuteScript(
+  EXPECT_TRUE(ExecuteScriptWithoutUserGesture(
       popup,
       "window.opener.location ='data:html/text;base64,'+btoa('payload');"));
   observer.WaitForFinished();
   histograms.ExpectUniqueSample("Navigation.DownloadPolicy",
-                                NavigationDownloadPolicy::kAllowOpener, 1);
+                                NavigationDownloadPolicy::kAllowOpenerNoGesture,
+                                1);
 }
 
 }  // namespace content