Perform direct routing of mouse events when the pointer is locked.

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 155 matching lines @@
   if (iter == owner_map_.end())
     return root_view;
 
   return iter->second;
 }
 
 void RenderWidgetHostInputEventRouter::RouteMouseEvent(
     RenderWidgetHostViewBase* root_view,
     blink::WebMouseEvent* event,
     const ui::LatencyInfo& latency) {
   RenderWidgetHostViewBase* target;

[Charlie Reis, 2017/02/15 21:38:49]

Given all the conditional assignments below, let's assign this to nullptr to
avoid any risk of uninitialized reads (e.g., after future refactors).

[lfg, 2017/02/15 22:02:48]

Done.

   gfx::Point transformed_point;
+
+  if (root_view->IsMouseLocked()) {

[Charlie Reis, 2017/02/15 21:38:49]

It's probably worth putting a comment on this block, given that it handles mouse
lock specially and then early returns.

[lfg, 2017/02/15 22:02:48]

Done.

+    target = RenderWidgetHostImpl::From(root_view->GetRenderWidgetHost())
+                 ->delegate()
+                 ->MouseLockWidget()
+                 ->GetView();
+    if (!root_view->TransformPointToCoordSpaceForView(
+            gfx::Point(event->x, event->y), target, &transformed_point))
+      return;
+
+    event->x = transformed_point.x();
+    event->y = transformed_point.y();
+    target->ProcessMouseEvent(*event, latency);
+    return;
+  }
+
   const int mouse_button_modifiers = blink::WebInputEvent::LeftButtonDown |
                                      blink::WebInputEvent::MiddleButtonDown |
                                      blink::WebInputEvent::RightButtonDown;
   if (mouse_capture_target_.target &&
       event->type() != blink::WebInputEvent::MouseDown &&
       (event->type() == blink::WebInputEvent::MouseUp ||
        event->modifiers() & mouse_button_modifiers)) {
     target = mouse_capture_target_.target;
     if (!root_view->TransformPointToCoordSpaceForView(
             gfx::Point(event->x, event->y), target, &transformed_point))
@@ skipping 52 matching lines @@
 
   event->x = transformed_point.x();
   event->y = transformed_point.y();
   target->ProcessMouseEvent(*event, latency);
 }
 
 void RenderWidgetHostInputEventRouter::RouteMouseWheelEvent(
     RenderWidgetHostViewBase* root_view,
     blink::WebMouseWheelEvent* event,
     const ui::LatencyInfo& latency) {
+  if (root_view->IsMouseLocked()) {
+    RenderWidgetHostImpl::From(root_view->GetRenderWidgetHost())
+        ->delegate()
+        ->MouseLockWidget()
+        ->GetView()
+        ->ProcessMouseEvent(*event, latency);
+    return;
+  }
+
   gfx::Point transformed_point;
   RenderWidgetHostViewBase* target = FindEventTarget(
       root_view, gfx::Point(event->x, event->y), &transformed_point);
   if (!target)
     return;
 
   event->x = transformed_point.x();
   event->y = transformed_point.y();
   target->ProcessMouseWheelEvent(*event, latency);
 }
@@ skipping 519 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