Added UMA collection for fullscreen / mouse lock bubble re-shows.

chrome/browser/ui/exclusive_access/mouse_lock_controller.cc

Index: chrome/browser/ui/exclusive_access/mouse_lock_controller.cc
diff --git a/chrome/browser/ui/exclusive_access/mouse_lock_controller.cc b/chrome/browser/ui/exclusive_access/mouse_lock_controller.cc
index a22df90e66500a96373f61379be54a11f78454b4..380f554b2beb9420bee4931ac17edc4846839455 100644
--- a/chrome/browser/ui/exclusive_access/mouse_lock_controller.cc
+++ b/chrome/browser/ui/exclusive_access/mouse_lock_controller.cc
@@ -116,6 +116,10 @@ void MouseLockController::NotifyTabExclusiveAccessLost() {
   }
 }
 
+const char* MouseLockController::HistogramPrefix() {
+  return "MouseLock";
+}
+
 bool MouseLockController::HandleUserPressedEscape() {
   if (IsMouseLocked() || IsMouseLockRequested()) {
     ExitExclusiveAccessIfNecessary();
@@ -188,6 +192,7 @@ bool MouseLockController::OnDenyExclusiveAccessPermission() {
 }
 
 void MouseLockController::LostMouseLock() {
+  Exiting();
   mouse_lock_state_ = MOUSELOCK_NOT_REQUESTED;
   SetTabWithExclusiveAccess(nullptr);
   NotifyMouseLockChange();