[PointerLock] Move "silent mouse lock" logic from renderer to RWHI

content/browser/renderer_host/render_widget_host_impl.cc

 // Copyright (c) 2012 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_impl.h"
 
 #include <math.h>
 
 #include <set>
 #include <tuple>
@@ skipping 268 matching lines @@
       is_unresponsive_(false),
       in_flight_event_count_(0),
       in_get_backing_store_(false),
       ignore_input_events_(false),
       text_direction_updated_(false),
       text_direction_(blink::kWebTextDirectionLeftToRight),
       text_direction_canceled_(false),
       suppress_events_until_keydown_(false),
       pending_mouse_lock_request_(false),
       allow_privileged_mouse_lock_(false),
+      is_last_unlocked_by_target_(false),
       has_touch_handler_(false),
       is_in_touchpad_gesture_fling_(false),
       latency_tracker_(),
       next_browser_snapshot_id_(1),
       owned_by_render_frame_host_(false),
       is_focused_(false),
       hung_renderer_delay_(
           base::TimeDelta::FromMilliseconds(kHungRendererDelayMs)),
       hang_monitor_event_type_(blink::WebInputEvent::kUndefined),
       last_event_type_(blink::WebInputEvent::kUndefined),
@@ skipping 1762 matching lines @@
   if (view_)
     view_->ImeCompositionRangeChanged(range, character_bounds);
 }
 
 void RenderWidgetHostImpl::OnImeCancelComposition() {
   if (view_)
     view_->ImeCancelComposition();
 }
 
 void RenderWidgetHostImpl::OnLockMouse(bool user_gesture,
-                                       bool last_unlocked_by_target,
                                        bool privileged) {
   if (pending_mouse_lock_request_) {
     Send(new ViewMsg_LockMouse_ACK(routing_id_, false));
     return;
   }
 
   pending_mouse_lock_request_ = true;
   if (delegate_) {
-    delegate_->RequestToLockMouse(this, user_gesture, last_unlocked_by_target,
+    delegate_->RequestToLockMouse(this, user_gesture,
+                                  is_last_unlocked_by_target_,
                                   privileged && allow_privileged_mouse_lock_);
+    // We need to reset |is_last_unlocked_by_target_| here as we don't know
+    // request source in |LostMouseLock()|.
+    is_last_unlocked_by_target_ = false;
     return;
   }
 
   if (privileged && allow_privileged_mouse_lock_) {
     // Directly approve to lock the mouse.
     GotResponseToLockMouseRequest(true);
   } else {
     // Otherwise, just reject it.
     GotResponseToLockMouseRequest(false);
   }
 }
 
 void RenderWidgetHostImpl::OnUnlockMouse() {
-  RejectMouseLockOrUnlockIfNecessary();
+  if (!pending_mouse_lock_request_ && IsMouseLocked()) {
+    // Got unlock request from renderer. Otherwise we only got |LostMouseLock()|
+    // if user unlocked mouse by pressing ESC.
+    is_last_unlocked_by_target_ = true;
+    view_->UnlockMouse();
+  }

[chongz, 2017/06/01 14:58:20]

Actually I don't think we should use |RejectMouseLockOrUnlockIfNecessary()|
here. |RejectMouseLockOrUnlockIfNecessary()| might 1. Reject lock request, or 2.
Automatically unlock mouse, which should only be used on destruction.

Moved unlock logic here instead of passing the boolean bit.

[dtapuska, 2017/06/05 14:49:49]

This pending_mouse_lock_request boolean is a little odd since it appears to all
be synchronous. Is this possibly some dead code that we might be able to get rid
of? See
https://chromium.googlesource.com/chromium/src/+/b6adb5143ab0cc79a64c64a42f96...

Maybe we can just change the RequestToLockMouse to actually be a boolean return
value?

[chongz, 2017/06/05 15:33:57]

Added back |RejectMouseLockOrUnlockIfNecessary()| as per our offline discussion.
We could set |is_last_unlocked_by_target_ = true;| before calling
|RejectMouseLockOrUnlockIfNecessary()|, but I'm feeling doing it after would
make the code easier to reason about.

Filed crbug.com/729584 to track the cleanup.

 }
 
 void RenderWidgetHostImpl::OnShowDisambiguationPopup(
     const gfx::Rect& rect_pixels,
     const gfx::Size& size,
     const cc::SharedBitmapId& id) {
   DCHECK(!rect_pixels.IsEmpty());
   DCHECK(!size.IsEmpty());
 
   std::unique_ptr<cc::SharedBitmap> bitmap =
@@ skipping 554 matching lines @@
           device::mojom::WakeLockType::PreventDisplaySleep,
           device::mojom::WakeLockReason::ReasonOther, "GetSnapshot",
           std::move(request));
     }
   }
   return wake_lock_.get();
 }
 #endif
 
 }  // namespace content