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

content/browser/renderer_host/render_widget_host.cc

Index: content/browser/renderer_host/render_widget_host.cc
diff --git a/content/browser/renderer_host/render_widget_host.cc b/content/browser/renderer_host/render_widget_host.cc
index 01077f770a631292037d2f0339ef4fcc7748da86..dd7f10b634880ff1ce40d2d12d8ae19b429938ca 100644
--- a/content/browser/renderer_host/render_widget_host.cc
+++ b/content/browser/renderer_host/render_widget_host.cc
@@ -383,8 +383,7 @@ void RenderWidgetHost::Focus() {
 }
 
 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));
 }
@@ -398,8 +397,7 @@ void RenderWidgetHost::LostMouseLock() {
 }
 
 void RenderWidgetHost::ViewDestroyed() {
-  if (IsMouseLocked())
-    view_->UnlockMouse();
+  UnlockMouseIfNecessary();
 
   // TODO(evanm): tracking this may no longer be necessary;
   // eliminate this function if so.
@@ -801,6 +799,15 @@ void RenderWidgetHost::ImeCancelComposition() {
             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;
 }
@@ -1151,9 +1158,8 @@ void RenderWidgetHost::OnMsgDidActivateAcceleratedCompositing(bool activated) {
 }
 
 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));
@@ -1161,8 +1167,7 @@ void RenderWidgetHost::OnMsgLockMouse() {
 }
 
 void RenderWidgetHost::OnMsgUnlockMouse() {
-  if (IsMouseLocked())
-    view_->UnlockMouse();
+  UnlockMouseIfNecessary();
 }
 
 #if defined(OS_POSIX)