Detect if osk is visible on windows

ui/base/win/osk_display_manager.cc

 // Copyright 2016 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/base/win/osk_display_manager.h"
 
 #include <windows.h>
 #include <shellapi.h>
 #include <shlobj.h>
 #include <shobjidl.h>  // Must be before propkey.
@@ skipping 342 matching lines @@
                                       &common_program_files))) {
         return false;
       }
       common_program_files_path = common_program_files;
     }
     osk_path->insert(common_program_files_offset, common_program_files_path);
   }
   return !osk_path->empty();
 }
 
+bool OnScreenKeyboardDisplayManager::IsKeyboardVisible() {

[Peter Kasting, 2017/07/08 02:19:31]

This file already has CheckIfKeyboardVisible() above, which looks like a
stricter version of this check.  Having both these is confusing.  Can we unify? 
If not, can we make it really clear why these need to differ?

(I found this because I was checking to see whether other functions could
replace calls to e.g. IsWindowEnabled() with calls to this function, to which my
answer is "maybe".)

[girard, 2017/07/10 20:23:51]

Patchset 2 contains this fix. The refactor was a bit strange because of the
function's side-effects, but I think the new code is cleaner.

+  if (base::win::GetVersion() < base::win::VERSION_WIN8)
+    return false;
+  HWND osk = ::FindWindow(kOSKClassName, nullptr);
+  return !!::IsWindow(osk) && !!::IsWindowEnabled(osk);
+}
+
 }  // namespace ui