Prevent browser-side hit testing when page popup is selected

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 dadfadfe816da806aff45e8844aa067de69afaae..54f7647f90ec4c31cfc6409314d7a2eb57134d77 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -6091,13 +6091,17 @@ class ShowWidgetMessageFilter : public content::BrowserMessageFilter {
 
   gfx::Rect last_initial_rect() const { return initial_rect_; }
 
+  int last_routing_id() const { return routing_id_; }
+
   void Wait() {
     initial_rect_ = gfx::Rect();
+    routing_id_ = MSG_ROUTING_NONE;
     message_loop_runner_->Run();
   }
 
   void Reset() {
     initial_rect_ = gfx::Rect();
+    routing_id_ = MSG_ROUTING_NONE;
     message_loop_runner_ = new content::MessageLoopRunner;
   }
 
@@ -6122,11 +6126,13 @@ class ShowWidgetMessageFilter : public content::BrowserMessageFilter {
 
   void OnShowWidgetOnUI(int route_id, const gfx::Rect& initial_rect) {
     initial_rect_ = initial_rect;
+    routing_id_ = route_id;
     message_loop_runner_->Quit();
   }
 
   scoped_refptr<content::MessageLoopRunner> message_loop_runner_;
   gfx::Rect initial_rect_;
+  int routing_id_;
 
   DISALLOW_COPY_AND_ASSIGN(ShowWidgetMessageFilter);
 };
@@ -6189,6 +6195,47 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, PopupMenuTest) {
   EXPECT_EQ(popup_rect.x() - rwhv_root->GetViewBounds().x(), 354);
   EXPECT_EQ(popup_rect.y() - rwhv_root->GetViewBounds().y(), 94);
 #endif
+
+#if defined(OS_LINUX)
+  // Verify click-and-drag selection of popups still works on Linux with
+  // OOPIFs enabled. This is only necessary to test on Aura because Mac and
+  // Android use native widgets. Windows does not support this as UI
+  // convention (it requires separate clicks to open the menu and select an
+  // option). See https://crbug.com/703191.
+  int process_id = child_node->current_frame_host()->GetProcess()->GetID();
+  filter->Reset();
+  RenderWidgetHostInputEventRouter* router =
+      static_cast<WebContentsImpl*>(shell()->web_contents())
+          ->GetInputEventRouter();
+  // Re-open the select element.
+  click_event.x = 360;
+  click_event.y = 90;

[alexmos, 2017/03/23 22:25:18]

The 90 here seems weird to me, since it seems that the <select> sits at y=94
(from popup_rect.y() above), so to click it in root frame's coordinates,
wouldn't this need to be >94?  The test still works, so I'm probably just
confused by how the coordinates work out.

[kenrb, 2017/03/24 14:18:43]

The y >= 94 is for the position of the drop-down menu, which appears below the
element.

+  click_event.clickCount = 1;
+  router->RouteMouseEvent(rwhv_root, &click_event, ui::LatencyInfo());
+
+  filter->Wait();
+
+  RenderWidgetHostView* popup_view =
+      RenderWidgetHost::FromID(process_id, filter->last_routing_id())
+          ->GetView();
+
+  RenderWidgetHostMouseEventMonitor popup_monitor(
+      popup_view->GetRenderWidgetHost());
+
+  // Next send a mouse up directly targeting the first option, simulating a

[alexmos, 2017/03/23 22:25:18]

It'd actually be nice to target one of the other options, and then verify that
the selection was changed correctly, just like in the bug repro.  Might be worth
doing if it's easy.

[kenrb, 2017/03/24 14:18:43]

It turns out not to be easy -- if you look at the first patch set, I was trying
to do exactly that. Unfortunately to select an option in the menu you have to
send a MouseMove, which causes flakiness in content_browsertests, and would
necessitate creating a new test in interactive_ui_tests instead. Since we are
just trying to catch a specific case (i.e. verifying that popups are exempt from
mouse capture), this simpler test condition seemed adequate.

+  // drag. This requires a ui::MouseEvent because it tests behavior that is
+  // above RWH input event routing.
+  ui::MouseEvent mouse_up_event(ui::ET_MOUSE_RELEASED, gfx::Point(10, 5),
+                                gfx::Point(10, 5), ui::EventTimeForNow(),
+                                ui::EF_LEFT_MOUSE_BUTTON,
+                                ui::EF_LEFT_MOUSE_BUTTON);
+  static_cast<RenderWidgetHostViewAura*>(popup_view)
+      ->OnMouseEvent(&mouse_up_event);
+
+  // This verifies that the popup actually received the event, and it wasn't
+  // diverted to a different RenderWidgetHostView due to mouse capture.
+  EXPECT_TRUE(popup_monitor.EventWasReceived());
+#endif
 }
 
 // Test that clicking a select element in a nested out-of-process iframe creates