Do not save/restore window state for client with BoundsMode::CLIENT.

components/exo/shell_surface.h

Index: components/exo/shell_surface.h
diff --git a/components/exo/shell_surface.h b/components/exo/shell_surface.h
index 80c93ea7ee64e2b5348e9e30efa6e2d12097c74b..1356c9a4a21f503b45d40f2fd8e22862b17bee95 100644
--- a/components/exo/shell_surface.h
+++ b/components/exo/shell_surface.h
@@ -225,6 +225,11 @@ class ShellSurface : public SurfaceDelegate,
   bool CanMaximize() const override;
   bool CanMinimize() const override;
   base::string16 GetWindowTitle() const override;
+  void SaveWindowPlacement(const gfx::Rect& bounds,
+                           ui::WindowShowState show_state) override;
+  bool GetSavedWindowPlacement(const views::Widget* widget,
+                               gfx::Rect* bounds,
+                               ui::WindowShowState* show_state) const override;
   void WindowClosing() override;
   views::Widget* GetWidget() override;
   const views::Widget* GetWidget() const override;