Revert of Moves definitions of RootWindowController into...

Revert of Moves definitions of RootWindowController into root_window_controller.cc (patchset #2 id:20001 of https://codereview.chromium.org/2628973002/ )

Reason for revert:
Attempting to resolve error in
https://uberchromegw.corp.google.com/i/chromium.chromiumos/builders/ChromiumOS%20amd64-generic%20Compile/builds/28853

>On 2017/01/11 22:44:48, James Cook wrote:
>> FYI I have a CL that deletes this method. We'll see who lands first.
> Done.

It looks like jamescook@ committed a bit more than four minutes earlier.
-- sheriff.

Original issue's description:
> Moves definitions of RootWindowController into root_window_controller.cc
>
> As part of this I made sure the definitions and declarations matched
> up. This resulted in reordering a couple of things. In addition the
> only other non-move I did was moving what was CreateLayoutManagers()
> into InitLayoutManagers() and CloseChildWindowsImpl() into
> CloseChildWindows().
>
> BUG=671246
> TEST=none
> R=jamescook@chromium.org
>
> Review-Url: https://codereview.chromium.org/2628973002
> Cr-Commit-Position: refs/heads/master@{#443109}
> Committed: https://chromium.googlesource.com/chromium/src/+/d20a89e7b56ad53a58f19edf4775528d066577d5

TBR=jamescook@chromium.org,sky@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=671246

Review-Url: https://codereview.chromium.org/2623393002
Cr-Commit-Position: refs/heads/master@{#443117}

ash/BUILD.gn

@@ -595,6 +595,7 @@ component("ash") {
     "common/wm_layout_manager.h",
     "common/wm_lookup.cc",
     "common/wm_lookup.h",
+    "common/wm_root_window_controller.cc",
     "common/wm_shell.cc",
     "common/wm_shell.h",
     "common/wm_transient_window_observer.h",

ash/root_window_controller.h

@@ -306,6 +306,10 @@ class ASH_EXPORT RootWindowController : public ShellObserver {
   // Creates the containers (WmWindows) used by the shell.
   void CreateContainers();
 
+  // Creates the LayoutManagers for the windows created by CreateContainers().
+  // TODO(sky): merge this with InitLayoutManagers().
+  void CreateLayoutManagers();
+
   // Initializes |system_wallpaper_| and possibly also |boot_splash_screen_|.
   // The initial color is determined by the |root_window_type| and whether or
   // not this is the first boot.
@@ -329,6 +333,9 @@ class ASH_EXPORT RootWindowController : public ShellObserver {
   void OnLoginStateChanged(LoginStatus status) override;
   void OnTouchHudProjectionToggled(bool enabled) override;
 
+  // TODO(sky): temporary, fold into CloseChildWindows().
+  void CloseChildWindowsImpl();
+
   std::unique_ptr<AshWindowTreeHost> ash_host_;
   std::unique_ptr<aura::WindowTreeHost> mus_window_tree_host_;
   // This comes from |ash_host_| or |mus_window_tree_host_|.