mash: Migrate ShelfLayoutManager ScreenUtil usage to ash common types.

ash/common/wm/wm_screen_util.cc

Index: ash/common/wm/wm_screen_util.cc
diff --git a/ash/common/wm/wm_screen_util.cc b/ash/common/wm/wm_screen_util.cc
index 92a268fb4cd8ef4ee6a6bc162109f267e5ca49fd..61af6f65a2623c7f2c8ac734f8ed86b7cbcd4ebe 100644
--- a/ash/common/wm/wm_screen_util.cc
+++ b/ash/common/wm/wm_screen_util.cc
@@ -5,8 +5,11 @@
 #include "ash/common/wm/wm_screen_util.h"
 
 #include "ash/common/wm_root_window_controller.h"
+#include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "ui/display/display.h"
+#include "ui/display/screen.h"
+#include "ui/gfx/geometry/size_conversions.h"
 
 namespace ash {
 namespace wm {
@@ -32,5 +35,17 @@ gfx::Rect GetMaximizedWindowBoundsInParent(WmWindow* window) {
   return GetDisplayBoundsInParent(window);
 }
 
+gfx::Rect GetShelfDisplayBoundsForWindow(WmWindow* window) {
+  if (WmShell::Get()->IsInUnifiedMode()) {
+    // In unified desktop mode, there is only one shelf in the first display.
+    gfx::SizeF size(WmShell::Get()->GetFirstDisplay().size());
+    float scale = window->GetRootWindow()->GetBounds().height() / size.height();
+    size.Scale(scale, scale);
+    return gfx::Rect(gfx::ToCeiledSize(size));
+  }

[James Cook, 2016/08/05 23:51:25]

Just FYI, taking out the in_mus() pieces of this function may break autohide in
mojo:sysui. I added them in https://codereview.chromium.org/2007003002. That
said, I think removing the code is the right thing to do, since sysui is going
away soon.

[msw, 2016/08/06 00:08:13]

Yeah, I though it would break mash shelf layout, and figured I'd leave a TODO
here (similar to the prior patch set), but it doesn't break mash shelf layout
afaict, and it's not clear what the correct pattern should be, given that my
prior patch set's use of GetRootWindowForDisplayId caused test crashes when
changing display configurations. I think we might need a fairly different
approach as mash begins to support the display manager and multiple displays,
but I'm not sure what if anything we should leave here.

+
+  return window->GetRootWindow()->GetBounds();
+}
+
 }  // namespace wm
 }  // namespace ash