Only allow to lock the mouse when the tab is in fullscreen mode.

content/browser/renderer_host/render_widget_host.cc

 // Copyright (c) 2011 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.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/i18n/rtl.h"
@@ skipping 364 matching lines @@
 }
 
 void RenderWidgetHost::GotFocus() {
   Focus();
 }
 
 void RenderWidgetHost::Focus() {
   Send(new ViewMsg_SetFocus(routing_id_, true));
 }
 
 void RenderWidgetHost::Blur() {

[sky, 2011/09/28 22:58:04]

What if the user minimizes the window when you have mouse lock?

[yzshen1, 2011/09/29 20:41:04]

Chrome will lose focus so it exits the mouse lock mode.
(I haven't tested platforms other than Windows, though. Because support for
mouse lock on other platforms hasn't been checked in yet.)

-  if (IsMouseLocked())
-    view_->UnlockMouse();
+  UnlockMouseIfNecessary();
 
   Send(new ViewMsg_SetFocus(routing_id_, false));
 }
 
 void RenderWidgetHost::LostCapture() {
   Send(new ViewMsg_MouseCaptureLost(routing_id_));
 }
 
 void RenderWidgetHost::LostMouseLock() {
   Send(new ViewMsg_MouseLockLost(routing_id_));
 }
 
 void RenderWidgetHost::ViewDestroyed() {
-  if (IsMouseLocked())
-    view_->UnlockMouse();
+  UnlockMouseIfNecessary();
 
   // TODO(evanm): tracking this may no longer be necessary;
   // eliminate this function if so.
   SetView(NULL);
 }
 
 void RenderWidgetHost::SetIsLoading(bool is_loading) {
   is_loading_ = is_loading;
   if (!view_)
     return;
@@ skipping 381 matching lines @@
 
 void RenderWidgetHost::ImeConfirmComposition() {
   Send(new ViewMsg_ImeConfirmComposition(routing_id(), string16()));
 }
 
 void RenderWidgetHost::ImeCancelComposition() {
   Send(new ViewMsg_ImeSetComposition(routing_id(), string16(),
             std::vector<WebKit::WebCompositionUnderline>(), 0, 0));
 }
 
+bool RenderWidgetHost::HasMouseLockPermission() const {
+  return false;
+}
+
+void RenderWidgetHost::UnlockMouseIfNecessary() {
+  if (IsMouseLocked())
+    view_->UnlockMouse();
+}
+
 bool RenderWidgetHost::IsMouseLocked() const {
   return view_ ? view_->mouse_locked() : false;
 }
 
 void RenderWidgetHost::Destroy() {
   NotificationService::current()->Notify(
       content::NOTIFICATION_RENDER_WIDGET_HOST_DESTROYED,
       Source<RenderWidgetHost>(this),
       NotificationService::NoDetails());
 
@@ skipping 330 matching lines @@
 #elif defined(OS_WIN)
   if (view_)
     view_->ShowCompositorHostWindow(is_accelerated_compositing_active_);
 #elif defined(TOOLKIT_USES_GTK)
   if (view_)
     view_->AcceleratedCompositingActivated(activated);
 #endif
 }
 
 void RenderWidgetHost::OnMsgLockMouse() {
-  // TODO(yzshen): Only allow to lock the mouse when in fullscreen mode, and
-  // make sure that the mouse is unlocked when leaving fullscreen mode.
-  if (!view_ || !view_->HasFocus() || !view_->LockMouse()) {
+  if (!HasMouseLockPermission() || !view_ || !view_->HasFocus()||
+      !view_->LockMouse()) {
     Send(new ViewMsg_LockMouse_ACK(routing_id_, false));
   } else {
     Send(new ViewMsg_LockMouse_ACK(routing_id_, true));
   }
 }
 
 void RenderWidgetHost::OnMsgUnlockMouse() {
-  if (IsMouseLocked())
-    view_->UnlockMouse();
+  UnlockMouseIfNecessary();
 }
 
 #if defined(OS_POSIX)
 void RenderWidgetHost::OnMsgGetScreenInfo(gfx::NativeViewId window_id,
                                           WebKit::WebScreenInfo* results) {
   if (view_)
     view_->GetScreenInfo(results);
   else
     RenderWidgetHostView::GetDefaultScreenInfo(results);
 }
@@ skipping 205 matching lines @@
 void RenderWidgetHost::Delete() {
   Send(new ViewMsg_Delete(routing_id()));
   UserMetrics::RecordAction(UserMetricsAction("DeleteSelection"));
 }
 
 void RenderWidgetHost::SelectAll() {
   Send(new ViewMsg_SelectAll(routing_id()));
   UserMetrics::RecordAction(UserMetricsAction("SelectAll"));
 }