Converts ash to use aura-mus

ash/mus/bridge/wm_window_mus_test_api.h

Index: ash/mus/bridge/wm_window_mus_test_api.h
diff --git a/ash/mus/bridge/wm_window_mus_test_api.h b/ash/mus/bridge/wm_window_mus_test_api.h
index aa064861aa1bc303ffc101cbe23bd7ffbd8e6c46..6848ff051ba10bf814cc2c5779dde4e4f6a4c075 100644
--- a/ash/mus/bridge/wm_window_mus_test_api.h
+++ b/ash/mus/bridge/wm_window_mus_test_api.h
@@ -12,6 +12,20 @@ namespace mus {
 
 class WmWindowMusTestApi {
  public:
+  // Used by tests to set the default value of\

[James Cook, 2016/12/05 19:21:44]

nit: eliminate \

[sky, 2016/12/05 21:39:19]

Done.

+  // |WmWindowMus::default_use_empty_minimum_size_for_testing_|.
+  class GlobalMinimumSizeLock {

[James Cook, 2016/12/05 19:21:44]

nit: document why this must exist. Do some tests call into shared code that
changes empty-min-size? Do windows have to be constructed with the param
initially set?

[sky, 2016/12/05 21:39:19]

Done.

+   public:
+    GlobalMinimumSizeLock();
+    ~GlobalMinimumSizeLock();
+
+   private:
+    // Number of instances of GlobalMinimumSizeLock that have been created.
+    static int instance_count_;
+
+    DISALLOW_COPY_AND_ASSIGN(GlobalMinimumSizeLock);
+  };
+
   explicit WmWindowMusTestApi(WmWindow* window)
       : WmWindowMusTestApi(WmWindowMus::AsWmWindowMus(window)) {}
   explicit WmWindowMusTestApi(WmWindowMus* window) : window_(window) {}
@@ -22,6 +36,8 @@ class WmWindowMusTestApi {
   }
 
  private:
+  static void SetDefaultUseEmptyMinimumSizeForTesting(bool value);
+
   WmWindowMus* window_;
 
   DISALLOW_COPY_AND_ASSIGN(WmWindowMusTestApi);