mash: Add WmShell::SetDisplayWorkAreaInsets for ShelfLayoutManager.

ash/common/wm_shell.h

Index: ash/common/wm_shell.h
diff --git a/ash/common/wm_shell.h b/ash/common/wm_shell.h
index 790809a04ff5439e65cc8d56d170fc882ce10a30..b55e1135837ab17f84292dd0c1e0a0fcb2389053 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -23,6 +23,7 @@ class Display;
 }
 
 namespace gfx {
+class Insets;
 class Point;
 }
 
@@ -188,6 +189,10 @@ class ASH_EXPORT WmShell {
   // the window size.
   virtual bool IsForceMaximizeOnFirstRun() = 0;
 
+  // Sets the work area insets of the display with |window|, notifies observers.

[James Cook, 2016/08/08 23:40:04]

super nit: "display containing |window|" maybe?

[msw, 2016/08/08 23:58:39]

Done.

+  virtual void SetDisplayWorkAreaInsets(WmWindow* window,
+                                        const gfx::Insets& insets) = 0;
+
   // Returns true if a system-modal dialog window is currently open.
   bool IsSystemModalWindowOpen();