Don't rely on untrusted events in site isolation browser test.

content/browser/site_per_process_browsertest.cc

Index: content/browser/site_per_process_browsertest.cc
diff --git a/content/browser/site_per_process_browsertest.cc b/content/browser/site_per_process_browsertest.cc
index 69bc8e72a511bdb594684598515068458351d1c4..f5586e70bb5eadb3909b2a3e7a3aa05b16ca04e4 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -7068,19 +7068,27 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
   NavigateFrameToURL(child2, embedded_test_server()->GetURL(
       "c.com", "/site_isolation/page-with-select.html"));
 
+  NativeWebKeyboardEvent event;
+  event.text[0] = ' ';

[Charlie Reis, 2016/06/16 22:35:23]

This isn't entirely clear to me at first glance.  I suppose hitting space when a
select menu is focused opens it?  Maybe you can update the comment below (saying
that and explaining the bit about untrusted events), and then put this event
declaration below the comment?

+  event.timeStampSeconds = 100;
+  event.type = blink::WebKeyboardEvent::Char;
   // Open both <select> menus.  This creates a popup widget in both processes.
   // Wait for and then drop the ViewHostMsg_ShowWidget messages, so that both
   // widgets are left in pending-but-not-shown state.
   scoped_refptr<PendingWidgetMessageFilter> filter1 =
       new PendingWidgetMessageFilter();
   process1->AddFilter(filter1.get());
-  EXPECT_TRUE(ExecuteScript(child1, "openSelectMenu();"));
+  EXPECT_TRUE(ExecuteScript(child1, "focusSelectMenu();"));
+  child1->current_frame_host()->GetRenderWidgetHost()->ForwardKeyboardEvent(
+      event);
   filter1->Wait();
 
   scoped_refptr<PendingWidgetMessageFilter> filter2 =
       new PendingWidgetMessageFilter();
   process2->AddFilter(filter2.get());
-  EXPECT_TRUE(ExecuteScript(child2, "openSelectMenu();"));
+  EXPECT_TRUE(ExecuteScript(child2, "focusSelectMenu();"));
+  child2->current_frame_host()->GetRenderWidgetHost()->ForwardKeyboardEvent(
+      event);
   filter2->Wait();
 
   // At this point, we should have two pending widgets.