Remove the CHECK from the DirectManipulationHelper::Activate function as it is firing in Canary on …

ui/views/win/hwnd_message_handler.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 "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 
@@ skipping 2502 matching lines @@
           "440919 HWNDMessageHandler::OnWindowPosChanged"));
 
   if (DidClientAreaSizeChange(window_pos))
     ClientAreaSizeChanged();
   if (remove_standard_frame_ && window_pos->flags & SWP_FRAMECHANGED &&
       ui::win::IsAeroGlassEnabled() &&
       (window_ex_style() & WS_EX_COMPOSITED) == 0) {
     MARGINS m = {10, 10, 10, 10};
     DwmExtendFrameIntoClientArea(hwnd(), &m);
   }
-  if (window_pos->flags & SWP_SHOWWINDOW)
+  if (window_pos->flags & SWP_SHOWWINDOW) {
     delegate_->HandleVisibilityChanged(true);
-  else if (window_pos->flags & SWP_HIDEWINDOW)
+    if (direct_manipulation_helper_)
+      direct_manipulation_helper_->Activate(hwnd());
+  } else if (window_pos->flags & SWP_HIDEWINDOW) {
     delegate_->HandleVisibilityChanged(false);
+    if (direct_manipulation_helper_)
+      direct_manipulation_helper_->Deactivate(hwnd());
+  }
   SetMsgHandled(FALSE);
 }
 
 void HWNDMessageHandler::OnSessionChange(WPARAM status_code) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "440919 HWNDMessageHandler::OnSessionChange"));
 
   // Direct3D presents are ignored while the screen is locked, so force the
@@ skipping 242 matching lines @@
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_HIDEWINDOW);
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_SHOWWINDOW);
   }
   // WM_DWMCOMPOSITIONCHANGED is only sent to top level windows, however we want
   // to notify our children too, since we can have MDI child windows who need to
   // update their appearance.
   EnumChildWindows(hwnd(), &SendDwmCompositionChanged, NULL);
 }
 
 }  // namespace views