A window should not get activated or get input focus if it's behind the lock screen.

ui/views/widget/native_widget_aura.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/widget/native_widget_aura.h"
 
 #include "base/bind.h"
 #include "base/strings/string_util.h"
 #include "build/build_config.h"
 #include "third_party/skia/include/core/SkRegion.h"
@@ skipping 477 matching lines @@
       state == ui::SHOW_STATE_DOCKED) {
     window_->SetProperty(aura::client::kShowStateKey, state);
   }
   window_->Show();
   if (delegate_->CanActivate()) {
     if (state != ui::SHOW_STATE_INACTIVE)
       Activate();
     // SetInitialFocus() should be always be called, even for
     // SHOW_STATE_INACTIVE. If the window has to stay inactive, the method will
     // do the right thing.
-    SetInitialFocus(state);
+    // Activate() might fail if the window is non-activatable. In this case, we
+    // should pass SHOW_STATE_INACTIVE to SetInitialFocus() to stop the initial
+    // focused view from getting focused. See crbug.com/515594 for example.
+    SetInitialFocus(IsActive() ? state : ui::SHOW_STATE_INACTIVE);
   }
 
   // On desktop aura, a window is activated first even when it is shown as
   // minimized. Do the same for consistency.
   if (state == ui::SHOW_STATE_MINIMIZED)
     Minimize();
 }
 
 bool NativeWidgetAura::IsVisible() const {
   return window_ && window_->IsVisible();
@@ skipping 658 matching lines @@
   l10n_util::AdjustUIFont(&(ncm.lfCaptionFont));
   base::win::ScopedHFONT caption_font(CreateFontIndirect(&(ncm.lfCaptionFont)));
   return gfx::FontList(gfx::Font(caption_font.get()));
 #else
   return gfx::FontList();
 #endif
 }
 
 }  // namespace internal
 }  // namespace views