Don't process event in immersive wide frame unless it's revealed

Bug: b/33693796
Test: manually tested with spinly app.
Change-Id: Id9214a318892bce97fa7290e69dd467d8fa7ce6c
Reviewed-on: https://chromium-review.googlesource.com/1033341
Commit-Queue: Mitsuru Oshima (OOO 4/30 - 5/9) <oshima@chromium.org>
Reviewed-by: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554939}

ash/frame/header_view.h

@@ -98,6 +98,7 @@ class ASH_EXPORT HeaderView : public views::View,
   views::View* avatar_icon() const;
 
   bool in_immersive_mode() const { return in_immersive_mode_; }
+  bool is_revealed() const { return fullscreen_visible_fraction_ > 0.0; }
 
   void set_title(const base::string16& title) {
     frame_header_->set_title(title);

ash/frame/wide_frame_view.cc

@@ -11,11 +11,39 @@
 #include "ash/public/cpp/immersive/immersive_fullscreen_controller.h"
 #include "ash/public/cpp/window_properties.h"
 #include "ui/aura/window.h"
+#include "ui/aura/window_targeter.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
+namespace {
+
+class WideFrameTargeter : public aura::WindowTargeter {
+ public:
+  WideFrameTargeter(HeaderView* header_view) : header_view_(header_view) {}
+  ~WideFrameTargeter() override = default;
+
+  // aura::WindowTargeter:
+  bool GetHitTestRects(aura::Window* target,
+                       gfx::Rect* hit_test_rect_mouse,
+                       gfx::Rect* hit_test_rect_touch) const override {
+    if (header_view_->in_immersive_mode() && !header_view_->is_revealed()) {
+      *hit_test_rect_mouse = target->bounds();
+      hit_test_rect_mouse->set_height(1);
+      hit_test_rect_mouse->SetRect(0, 0, 0, 0);
+      return true;
+    }
+    return aura::WindowTargeter::GetHitTestRects(target, hit_test_rect_mouse,
+                                                 hit_test_rect_touch);
+  }
+
+ private:
+  HeaderView* header_view_;
+  DISALLOW_COPY_AND_ASSIGN(WideFrameTargeter);
+};
+
+}  // namespace
 
 // static
 WideFrameView* WideFrameView::Create(views::Widget* target) {
@@ -31,6 +59,9 @@ WideFrameView* WideFrameView::Create(views::Widget* target) {
   params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
   widget->Init(params);
 
+  aura::Window* window = widget->GetNativeWindow();
+  window->SetEventTargeter(
+      std::make_unique<WideFrameTargeter>(frame_view->header_view()));
   return frame_view;
 }