Revert of Do not interchange MOUSE_MOVED and MOUSE_DRAGGED events in Widget (patchset #8 id:140001 of https://codereview.chromium.org/560053002/)

Reason for revert:
Responsible for the crash reported in crbug.com/430427. Relanding will require addressing crbug.com/431350 first.

Original issue's description:
> Do not interchange MOUSE_MOVED and MOUSE_DRAGGED events in Widget
>
> In Widget::OnMouseEvent(), do not handle MOUSE_MOVED
> events as MOUSE_DRAGGED events, and do not handle
> MOUSE_DRAGGED events as MOUSE_MOVED events; instead
> trust that the mouse event type has been set correctly
> before arriving at Widget. This also allows us to
> remove the member |is_mouse_button_pressed_|
> from Widget.
>
> BUG=412929, 412931
> TEST=WidgetTest.DragIntoView

BUG=412929, 412931
TBR=sadrul@chromium.org

Review URL: https://codereview.chromium.org/703643004

Cr-Commit-Position: refs/heads/master@{#303274}

5 files changed, 27 insertions, 92 deletions

diff --git a/ui/views/view_unittest.cc b/ui/views/view_unittest.cc
index aef5632..85c2f48 100644
--- a/ui/views/view_unittest.cc
+++ b/ui/views/view_unittest.cc
@@ -367,7 +367,7 @@ TEST_F(ViewTest, MouseEvent) {
   v2->Reset();
   ui::MouseEvent released(ui::ET_MOUSE_RELEASED, gfx::Point(), gfx::Point(), 0,
                           0);
-  root->OnMouseReleased(released);
+  root->OnMouseDragged(released);
   EXPECT_EQ(v2->last_mouse_event_type_, ui::ET_MOUSE_RELEASED);
   EXPECT_EQ(v2->location_.x(), -100);
   EXPECT_EQ(v2->location_.y(), -100);
diff --git a/ui/views/widget/root_view.cc b/ui/views/widget/root_view.cc
index c4cb51f..f282b9a 100644
--- a/ui/views/widget/root_view.cc
+++ b/ui/views/widget/root_view.cc
@@ -413,7 +413,6 @@ bool RootView::OnMousePressed(const ui::MouseEvent& event) {
 }
 
 bool RootView::OnMouseDragged(const ui::MouseEvent& event) {
-  CHECK_EQ(ui::ET_MOUSE_DRAGGED, event.type());
   if (mouse_pressed_handler_) {
     SetMouseLocationAndFlags(event);
 
@@ -471,7 +470,6 @@ void RootView::OnMouseCaptureLost() {
 }
 
 void RootView::OnMouseMoved(const ui::MouseEvent& event) {
-  CHECK_EQ(ui::ET_MOUSE_MOVED, event.type());
   View* v = GetEventHandlerForPoint(event.location());
   // Find the first enabled view, or the existing move handler, whichever comes
   // first.  The check for the existing handler is because if a view becomes
diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index 74bd54b..ae43a31 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -162,6 +162,7 @@ Widget::Widget()
       is_top_level_(false),
       native_widget_initialized_(false),
       native_widget_destroyed_(false),
+      is_mouse_button_pressed_(false),
       ignore_capture_loss_(false),
       last_mouse_event_was_move_(false),
       auto_release_capture_(true),
@@ -344,6 +345,10 @@ void Widget::Init(const InitParams& in_params) {
                    AsNativeWidgetPrivate();
   root_view_.reset(CreateRootView());
   default_theme_provider_.reset(new ui::DefaultThemeProvider);
+  if (params.type == InitParams::TYPE_MENU) {
+    is_mouse_button_pressed_ =
+        internal::NativeWidgetPrivate::IsMouseButtonDown();
+  }
   native_widget_->InitNativeWidget(params);
   if (RequiresNonClientView(params.type)) {
     non_client_view_ = new NonClientView;
@@ -941,6 +946,8 @@ void Widget::SetCapture(View* view) {
       return;
   }
 
+  if (internal::NativeWidgetPrivate::IsMouseButtonDown())
+    is_mouse_button_pressed_ = true;
   root_view_->SetMouseHandler(view);
 }
 
@@ -1181,12 +1188,11 @@ void Widget::OnKeyEvent(ui::KeyEvent* event) {
 //                   RootView from anywhere in Widget. Use
 //                   SendEventToProcessor() instead. See crbug.com/348087.
 void Widget::OnMouseEvent(ui::MouseEvent* event) {
-  if (event->type() != ui::ET_MOUSE_MOVED)
-    last_mouse_event_was_move_ = false;
-
   View* root_view = GetRootView();
   switch (event->type()) {
     case ui::ET_MOUSE_PRESSED: {
+      last_mouse_event_was_move_ = false;
+
       // We may get deleted by the time we return from OnMousePressed. So we
       // use an observer to make sure we are still alive.
       WidgetDeletionObserver widget_deletion_observer(this);
@@ -1204,6 +1210,7 @@ void Widget::OnMouseEvent(ui::MouseEvent* event) {
       if (root_view && root_view->OnMousePressed(*event) &&
           widget_deletion_observer.IsWidgetAlive() && IsVisible() &&
           internal::NativeWidgetPrivate::IsMouseButtonDown()) {
+        is_mouse_button_pressed_ = true;
         if (!native_widget_->HasCapture())
           native_widget_->SetCapture();
         event->SetHandled();
@@ -1212,6 +1219,8 @@ void Widget::OnMouseEvent(ui::MouseEvent* event) {
     }
 
     case ui::ET_MOUSE_RELEASED:
+      last_mouse_event_was_move_ = false;
+      is_mouse_button_pressed_ = false;
       // Release capture first, to avoid confusion if OnMouseReleased blocks.
       if (auto_release_capture_ && native_widget_->HasCapture()) {
         base::AutoReset<bool> resetter(&ignore_capture_loss_, true);
@@ -1224,8 +1233,13 @@ void Widget::OnMouseEvent(ui::MouseEvent* event) {
       return;
 
     case ui::ET_MOUSE_MOVED:
-      if (!last_mouse_event_was_move_ ||
-          last_mouse_event_position_ != event->location()) {
+    case ui::ET_MOUSE_DRAGGED:
+      if (native_widget_->HasCapture() && is_mouse_button_pressed_) {
+        last_mouse_event_was_move_ = false;
+        if (root_view)
+          root_view->OnMouseDragged(*event);
+      } else if (!last_mouse_event_was_move_ ||
+                 last_mouse_event_position_ != event->location()) {
         last_mouse_event_position_ = event->location();
         last_mouse_event_was_move_ = true;
         if (root_view)
@@ -1233,12 +1247,8 @@ void Widget::OnMouseEvent(ui::MouseEvent* event) {
       }
       return;
 
-    case ui::ET_MOUSE_DRAGGED:
-      if (root_view)
-        root_view->OnMouseDragged(*event);
-      return;
-
     case ui::ET_MOUSE_EXITED:
+      last_mouse_event_was_move_ = false;
       if (root_view)
         root_view->OnMouseExited(*event);
       return;
@@ -1261,6 +1271,7 @@ void Widget::OnMouseCaptureLost() {
   View* root_view = GetRootView();
   if (root_view)
     root_view->OnMouseCaptureLost();
+  is_mouse_button_pressed_ = false;
 }
 
 void Widget::OnScrollEvent(ui::ScrollEvent* event) {
diff --git a/ui/views/widget/widget.h b/ui/views/widget/widget.h
index fa7c771..c7e46d3 100644
--- a/ui/views/widget/widget.h
+++ b/ui/views/widget/widget.h
@@ -946,13 +946,17 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
   // Whether native widget has been destroyed.
   bool native_widget_destroyed_;
 
+  // TODO(beng): Remove NativeWidgetGtk's dependence on these:
+  // If true, the mouse is currently down.
+  bool is_mouse_button_pressed_;
+
   // True if capture losses should be ignored.
   bool ignore_capture_loss_;
 
+  // TODO(beng): Remove NativeWidgetGtk's dependence on these:
   // The following are used to detect duplicate mouse move events and not
   // deliver them. Displaying a window may result in the system generating
   // duplicate move events even though the mouse hasn't moved.
-  // TODO(tdanderson): We may be able to remove these members.
   bool last_mouse_event_was_move_;
   gfx::Point last_mouse_event_position_;
 
diff --git a/ui/views/widget/widget_unittest.cc b/ui/views/widget/widget_unittest.cc
index 7801c2d..1bbc384 100644
--- a/ui/views/widget/widget_unittest.cc
+++ b/ui/views/widget/widget_unittest.cc
@@ -3240,84 +3240,6 @@ TEST_F(WidgetTest, MouseEventTypesViaGenerator) {
   widget->CloseNow();
 }
 
-// Tests that a view does not receive entered, dragged, or moved events if
-// a mouse cursor is moved into it while the left mouse button is pressed.
-TEST_F(WidgetTest, DragIntoView) {
-  EventCountView* container = new EventCountView;
-  container->SetBounds(0, 0, 100, 80);
-
-  EventCountView* consume_view = new EventCountView;
-  consume_view->set_handle_mode(EventCountView::CONSUME_EVENTS);
-  consume_view->SetBounds(10, 10, 50, 40);
-
-  Widget* widget = CreateTopLevelFramelessPlatformWidget();
-  widget->SetBounds(gfx::Rect(0, 0, 100, 80));
-  widget->SetContentsView(container);
-  container->AddChildView(consume_view);
-
-  widget->Show();
-
-  ui::test::EventGenerator generator(GetContext(), widget->GetNativeWindow());
-  generator.set_current_location(gfx::Point(75, 15));
-
-  generator.PressLeftButton();
-  generator.MoveMouseTo(gfx::Point(20, 20));
-  EXPECT_EQ(0, consume_view->GetEventCount(ui::ET_MOUSE_ENTERED));
-  EXPECT_EQ(0, consume_view->GetEventCount(ui::ET_MOUSE_DRAGGED));
-  EXPECT_EQ(0, consume_view->GetEventCount(ui::ET_MOUSE_MOVED));
-
-  widget->CloseNow();
-}
-
-// Tests that a view receives the correct mouse events if a mouse cursor
-// is moved out of its bounds while the left mouse button is pressed.
-TEST_F(WidgetTest, DragOutOfView) {
-  EventCountView* container = new EventCountView;
-  container->SetBounds(0, 0, 100, 80);
-
-  EventCountView* consume_view = new EventCountView;
-  consume_view->set_handle_mode(EventCountView::CONSUME_EVENTS);
-  consume_view->SetBounds(10, 10, 50, 40);
-
-  Widget* widget = CreateTopLevelFramelessPlatformWidget();
-  widget->SetBounds(gfx::Rect(0, 0, 100, 80));
-  widget->SetContentsView(container);
-  container->AddChildView(consume_view);
-
-  widget->Show();
-
-  ui::test::EventGenerator generator(GetContext(), widget->GetNativeWindow());
-  generator.set_current_location(gfx::Point(20, 20));
-
-  generator.PressLeftButton();
-  EXPECT_EQ(1, consume_view->GetEventCount(ui::ET_MOUSE_PRESSED));
-  EXPECT_EQ(0, container->GetEventCount(ui::ET_MOUSE_PRESSED));
-  consume_view->ResetCounts();
-
-  generator.MoveMouseTo(gfx::Point(70, 70));
-  EXPECT_EQ(0, consume_view->GetEventCount(ui::ET_MOUSE_EXITED));
-  EXPECT_EQ(1, consume_view->GetEventCount(ui::ET_MOUSE_DRAGGED));
-  EXPECT_EQ(0, consume_view->GetEventCount(ui::ET_MOUSE_MOVED));
-  EXPECT_EQ(0, container->GetEventCount(ui::ET_MOUSE_ENTERED));
-  EXPECT_EQ(0, container->GetEventCount(ui::ET_MOUSE_DRAGGED));
-  EXPECT_EQ(0, container->GetEventCount(ui::ET_MOUSE_MOVED));
-  consume_view->ResetCounts();
-
-  generator.MoveMouseTo(gfx::Point(71, 71));
-  EXPECT_EQ(1, consume_view->GetEventCount(ui::ET_MOUSE_DRAGGED));
-  EXPECT_EQ(0, consume_view->GetEventCount(ui::ET_MOUSE_MOVED));
-  EXPECT_EQ(0, container->GetEventCount(ui::ET_MOUSE_DRAGGED));
-  EXPECT_EQ(0, container->GetEventCount(ui::ET_MOUSE_MOVED));
-  consume_view->ResetCounts();
-
-  generator.ReleaseLeftButton();
-  EXPECT_EQ(1, consume_view->GetEventCount(ui::ET_MOUSE_RELEASED));
-  EXPECT_EQ(0, container->GetEventCount(ui::ET_MOUSE_RELEASED));
-  consume_view->ResetCounts();
-
-  widget->CloseNow();
-}
-
 // Tests that the root view is correctly set up for Widget types that do not
 // require a non-client view, before any other views are added to the widget.
 // That is, before Widget::ReorderNativeViews() is called which, if called with