Fullscreen can't use the desktop as a parent in metro mode

Also moved the rootwindow stuff to the hwnd_util and cleaned it up.

BUG=118641
TEST=see bug
Review URL: https://chromiumcodereview.appspot.com/10270029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@134848 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 22 insertions, 25 deletions

diff --git a/ui/base/win/hwnd_util.cc b/ui/base/win/hwnd_util.cc
index 4da6594..38a7253 100644
--- a/ui/base/win/hwnd_util.cc
+++ b/ui/base/win/hwnd_util.cc
@@ -6,6 +6,7 @@
 
 #include "base/i18n/rtl.h"
 #include "base/string_util.h"
+#include "base/win/metro.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 
@@ -181,4 +182,18 @@ void ShowSystemMenu(HWND window, int screen_x, int screen_y) {
     SendMessage(window, WM_SYSCOMMAND, command, 0);
 }
 
+extern "C" {
+  typedef HWND (*RootWindow)();
+}
+
+HWND GetWindowToParentTo(bool get_real_hwnd) {
+  HMODULE metro = base::win::GetMetroModule();
+  if (!metro)
+    return get_real_hwnd ? ::GetDesktopWindow() : HWND_DESKTOP;
+  // In windows 8 metro-mode the root window is not the desktop.
+  RootWindow root_window =
+      reinterpret_cast<RootWindow>(::GetProcAddress(metro, "GetRootWindow"));
+  return root_window();
+}
+
 }  // namespace ui
diff --git a/ui/base/win/hwnd_util.h b/ui/base/win/hwnd_util.h
index 7fbe591..09f777a 100644
--- a/ui/base/win/hwnd_util.h
+++ b/ui/base/win/hwnd_util.h
@@ -47,6 +47,11 @@ UI_EXPORT void CheckWindowCreated(HWND hwnd);
 // user selected something.
 UI_EXPORT void ShowSystemMenu(HWND window, int screen_x, int screen_y);
 
+// Returns the window you can use to parent a top level window.
+// Note that in some cases we create child windows not parented to its final
+// container so in those cases you should pass true in |get_real_hwnd|.
+UI_EXPORT HWND GetWindowToParentTo(bool get_real_hwnd);
+
 }  // namespace ui
 
 #endif  // UI_BASE_WIN_HWND_UTIL_H_
diff --git a/ui/base/win/window_impl.cc b/ui/base/win/window_impl.cc
index 8221253..31d0fe3 100644
--- a/ui/base/win/window_impl.cc
+++ b/ui/base/win/window_impl.cc
@@ -12,29 +12,6 @@
 #include "base/win/wrapped_window_proc.h"
 #include "ui/base/win/hwnd_util.h"
 
-namespace {
-
-extern "C" {
-  typedef HWND (*GetRootWindow)();
-}
-
-HMODULE GetMetroDll() {
-  static HMODULE hm = ::GetModuleHandleA("metro_driver.dll");
-  return hm;
-}
-
-HWND RootWindow(bool is_child_window) {
-  HMODULE metro = GetMetroDll();
-  if (!metro) {
-    return is_child_window ? ::GetDesktopWindow() : HWND_DESKTOP;
-  }
-  GetRootWindow get_root_window =
-      reinterpret_cast<GetRootWindow>(::GetProcAddress(metro, "GetRootWindow"));
-  return get_root_window();
-}
-
-}  // namespace
-
 namespace ui {
 
 static const DWORD kWindowDefaultChildStyle =
@@ -164,10 +141,10 @@ void WindowImpl::Init(HWND parent, const gfx::Rect& bounds) {
   if (parent == HWND_DESKTOP) {
     // Only non-child windows can have HWND_DESKTOP (0) as their parent.
     CHECK((window_style_ & WS_CHILD) == 0);
-    parent = RootWindow(false);
+    parent = GetWindowToParentTo(false);
   } else if (parent == ::GetDesktopWindow()) {
     // Any type of window can have the "Desktop Window" as their parent.
-    parent = RootWindow(true);
+    parent = GetWindowToParentTo(true);
   } else if (parent != HWND_MESSAGE) {
     CHECK(::IsWindow(parent));
   }