Add support code to test the cast system tray item.

ash/system/cast/tray_cast.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_SYSTEM_CAST_TRAY_CAST_H_
 #define ASH_SYSTEM_CAST_TRAY_CAST_H_
 
+#include "ash/ash_export.h"
 #include "ash/cast_config_delegate.h"
 #include "ash/shell_observer.h"
 #include "ash/system/tray/system_tray_item.h"
 #include "base/memory/weak_ptr.h"
 
 namespace ash {
 namespace tray {
 class CastTrayView;
 class CastSelectDefaultView;
 class CastDetailedView;
 class CastDuplexView;
 }  // namespace tray
 
-class TrayCast : public SystemTrayItem, public ShellObserver {
+class ASH_EXPORT TrayCastTestMethods {

[achuithb, 2015/07/14 18:06:39]

TrayCastTestingInterface?

Does it compile if you move this definition to after the definition of TrayCast?
It's kind of unfortunate that the testing interface is the first thing you see
in this file. 

[jdufault, 2015/07/15 17:35:01]

Done.

I am unable to get it to compile moving it after TrayCast (I also tried using an
incomplete type).

[achuithb, 2015/07/15 18:56:47]

That's what I would expect if the compiler refuses to look ahead in the file.

How do you feel about putting it in a separate .h?

[jdufault, 2015/07/15 20:08:42]

Yes; I would have been surprised if it worked as well. I've moved the testing
interface into its own file.

+ public:
+  virtual bool IsTrayInitializedForTest() const = 0;
+  virtual bool IsTrayVisibleForTest() const = 0;
+  virtual bool IsTrayCastViewVisibleForTest() const = 0;

[achuithb, 2015/07/14 18:06:39]

Maybe add a comment explaining the different between this and the next function

[jdufault, 2015/07/15 17:35:01]

Done.

[achuithb, 2015/07/15 18:56:47]

I meant the difference between IsTrayCastViewVisibleForTest and
IsTraySelectViewVisibleForTest.

Also, the comments should go in the interface definition, not in the
implementation.

[jdufault, 2015/07/15 20:08:42]

Oops; done.

+  virtual bool IsTraySelectViewVisibleForTest() const = 0;
+  // Start a new cast to the given receiver.
+  virtual void StartCastForTest(const std::string& id) = 0;
+  virtual void StopCastForTest() = 0;
+
+  // Exposed callback to update the casting state. The test code needs to call
+  // this function manually, as there is no actual casting going on. In a real
+  // environment, this method is invoked by the casting system in Chrome.
+  virtual void OnCastingSessionStartedOrStopped(bool is_casting) = 0;
+};
+
+class ASH_EXPORT TrayCast : public SystemTrayItem,
+                            public ShellObserver,
+                            public TrayCastTestMethods {
  public:
   explicit TrayCast(SystemTray* system_tray);
   ~TrayCast() override;
 
  private:
+  // Overridden from TrayCastTestMethods:

[achuithb, 2015/07/14 18:06:39]

use a period to be consistent with the rest of this file

[jdufault, 2015/07/15 17:35:01]

Done.

+  bool IsTrayInitializedForTest() const override;
+  bool IsTrayVisibleForTest() const override;
+  bool IsTrayCastViewVisibleForTest() const override;
+  bool IsTraySelectViewVisibleForTest() const override;
+  void StartCastForTest(const std::string& id) override;
+  void StopCastForTest() override;
+
   // Overridden from SystemTrayItem.
   views::View* CreateTrayView(user::LoginStatus status) override;
   views::View* CreateDefaultView(user::LoginStatus status) override;
   views::View* CreateDetailedView(user::LoginStatus status) override;
   void DestroyTrayView() override;
   void DestroyDefaultView() override;
   void DestroyDetailedView() override;
   void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override;
 
   // Overridden from ShellObserver.
@@ skipping 23 matching lines @@
   bool has_cast_receivers_ = false;
   bool is_casting_ = false;
   base::WeakPtrFactory<TrayCast> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayCast);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CAST_TRAY_CAST_H_