Clear last MouseMove root view in RWHIER if that view gets destroyed

content/browser/renderer_host/render_widget_host_input_event_router.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_input_event_router.h"
 
 #include <vector>
 
 #include "base/metrics/histogram_macros.h"
 
@@ skipping 72 matching lines @@
     // When a child iframe is destroyed, consider its parent to be to be the
     // most recent target, if possible. In some cases the parent might already
     // have been destroyed, in which case the last target is cleared.
     if (view != last_mouse_move_root_view_)
       last_mouse_move_target_ =
           static_cast<RenderWidgetHostViewChildFrame*>(last_mouse_move_target_)
               ->GetParentView();
     else
       last_mouse_move_target_ = nullptr;
 
-    if (!last_mouse_move_target_)
+    if (!last_mouse_move_target_ || view == last_mouse_move_root_view_)
       last_mouse_move_root_view_ = nullptr;
   }
 }
 
 void RenderWidgetHostInputEventRouter::ClearAllObserverRegistrations() {
   for (auto entry : owner_map_)
     entry.second->RemoveObserver(this);
   owner_map_.clear();
 }
 
@@ skipping 271 matching lines @@
   // space.
   if (root_view != last_mouse_move_root_view_)
     last_mouse_move_target_ = nullptr;
 
   // Finding the LCA uses a standard approach. We build vectors of the
   // ancestors of each node up to the root, and then remove common ancestors.
   std::vector<RenderWidgetHostViewBase*> entered_views;
   std::vector<RenderWidgetHostViewBase*> exited_views;
   RenderWidgetHostViewBase* cur_view = target;
   entered_views.push_back(cur_view);
-  while (cur_view != root_view) {
-    // Non-root RWHVs are guaranteed to be RenderWidgetHostViewChildFrames.
+  while (cur_view->IsRenderWidgetHostViewChildFrame()) {
     cur_view =
         static_cast<RenderWidgetHostViewChildFrame*>(cur_view)->GetParentView();
     // cur_view can possibly be nullptr for guestviews that are not currently
     // connected to the webcontents tree.
-    if (!cur_view)
-      break;
+    if (!cur_view) {
+      last_mouse_move_target_ = target;
+      last_mouse_move_root_view_ = root_view;
+      return;
+    }
     entered_views.push_back(cur_view);
   }
+  // Non-root RWHVs are guaranteed to be RenderWidgetHostViewChildFrames,
+  // as long as they are the only embeddable RWHVs.
+  DCHECK_EQ(cur_view, root_view);
 
   cur_view = last_mouse_move_target_;
   if (cur_view) {
     exited_views.push_back(cur_view);
-    while (cur_view != root_view) {
+    while (cur_view->IsRenderWidgetHostViewChildFrame()) {
       cur_view = static_cast<RenderWidgetHostViewChildFrame*>(cur_view)
                      ->GetParentView();
-      if (!cur_view)
-        break;
+      if (!cur_view) {
+        last_mouse_move_target_ = target;
+        last_mouse_move_root_view_ = root_view;
+        return;
+      }
       exited_views.push_back(cur_view);
     }
+    DCHECK_EQ(cur_view, root_view);
   }
 
   // This removes common ancestors from the root downward.
   RenderWidgetHostViewBase* common_ancestor = nullptr;
   while (entered_views.size() > 0 && exited_views.size() > 0 &&
          entered_views.back() == exited_views.back()) {
     common_ancestor = entered_views.back();
     entered_views.pop_back();
     exited_views.pop_back();
   }
@@ skipping 313 matching lines @@
   if (!touchpad_gesture_target_.target)
     return;
 
   // TODO(mohsen): Add tests to check event location.
   event->x += touchpad_gesture_target_.delta.x();
   event->y += touchpad_gesture_target_.delta.y();
   touchpad_gesture_target_.target->ProcessGestureEvent(*event, latency);
 }
 
 }  // namespace content