No pointer captured when the pointer lock is applied

third_party/WebKit/Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 2172 matching lines @@
   UIEventWithKeyState::ClearNewTabModifierSetFromIsolatedWorld();
 
   bool is_pointer_locked = false;
   if (WebFrameWidgetBase* widget = MainFrameImpl()->FrameWidget()) {
     if (WebWidgetClient* client = widget->Client())
       is_pointer_locked = client->IsPointerLocked();
   }
 
   if (is_pointer_locked &&
       WebInputEvent::IsMouseEventType(input_event.GetType())) {
+    LocalFrame* focusedFrame = FocusedLocalFrameInWidget();
+    if (focusedFrame) {
+      WebMouseEvent transformed_event = TransformWebMouseEvent(
+          MainFrameImpl()->GetFrameView(),
+          static_cast<const WebMouseEvent&>(input_event));
+      Vector<WebMouseEvent> transformed_coalesced_events =
+          TransformWebMouseEventVector(
+              MainFrameImpl()->GetFrameView(),
+              coalesced_event.GetCoalescedEventsPointers());
+      focusedFrame->GetEventHandler().ProcessPendingPointerCapture(
+          transformed_event, transformed_coalesced_events);
+    }
+
     MainFrameImpl()->FrameWidget()->PointerLockMouseEvent(input_event);

[mustaq, 2017/05/19 20:05:33]

I believe we need a similar fix before another direct dispatch call which in
WebFrameWidgetImpl::HandleInputEvent.

But same fix in two places would be ugly. Perhaps move
WebFrameWidgetBase::PointerLockMouseEvent into EventHandler and call
ProcessPendingPointerCapture there?

Another related thought: these calls ultimately reach
PointerLockController::DispatchLockedMouseEvent where we synthesize a "click"
after a "mouseup".  Can we reuse the existing code around EventHandler for this,
perhaps by replacing calls to
  element_->DispatchMouseEvent
by calls to EventHandler methods?  This would also fix the PointerLock part of
crbug.com/665924.

[lanwei, 2017/05/23 23:11:42]

You are right, I moved the code to the WebFrameWidgetBase class, and add a todo.

     return WebInputEventResult::kHandledSystem;
   }
 
   if (mouse_capture_node_ &&
       WebInputEvent::IsMouseEventType(input_event.GetType())) {
     TRACE_EVENT1("input", "captured mouse event", "type",
                  input_event.GetType());
     // Save m_mouseCaptureNode since mouseCaptureLost() will clear it.
     Node* node = mouse_capture_node_;
 
@@ skipping 348 matching lines @@
   SetRootLayer(nullptr);
   animation_host_ = nullptr;
 
   mutator_ = nullptr;
   layer_tree_view_ = nullptr;
 }
 
 void WebViewImpl::DidAcquirePointerLock() {
   if (MainFrameImpl())
     MainFrameImpl()->FrameWidget()->DidAcquirePointerLock();
+
+  LocalFrame* focusedFrame = FocusedLocalFrameInWidget();
+  if (focusedFrame)
+    focusedFrame->GetEventHandler().ReleaseMousePointerCapture();
 }
 
 void WebViewImpl::DidNotAcquirePointerLock() {
   if (MainFrameImpl())
     MainFrameImpl()->FrameWidget()->DidNotAcquirePointerLock();
 }
 
 void WebViewImpl::DidLosePointerLock() {
   // Make sure that the main frame wasn't swapped-out when the pointer lock is
   // lost. There's a race that can happen when a pointer lock is requested, but
@@ skipping 1597 matching lines @@
   if (focused_frame->LocalFrameRoot() != MainFrameImpl()->GetFrame())
     return nullptr;
   return focused_frame;
 }
 
 LocalFrame* WebViewImpl::FocusedLocalFrameAvailableForIme() const {
   return ime_accept_events_ ? FocusedLocalFrameInWidget() : nullptr;
 }
 
 }  // namespace blink