Pull cast system gesture methods up to base window manager interface.

Background: Implementation of the side swipe system gesture handling
is present only in the CastWindowManagerAura implementation, but
actual users will only have a handle to the base CastWindowManager
interface. This CL pulls the methods up to the interface and leaves
them as stubs in the CastWindowManagerDefault.

Bug: b/71541742
Tested: Manual testing
Change-Id: Ib83e42b046153a0e680f8d76eda6d9c0e7bb655d
Reviewed-on: https://chromium-review.googlesource.com/891478Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Ryan Daum <rdaum@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532575}

chromecast/graphics/cast_window_manager.h

@@ -16,6 +16,8 @@ class Event;
 
 namespace chromecast {
 
+class CastSideSwipeGestureHandlerInterface;
+
 // Chromecast's window-manager interface.
 // This declares the interface to add top-level windows to the Chromecast
 // platform window.  It is owned by the UI thread, and generally one instance
@@ -57,6 +59,14 @@ class CastWindowManager {
 
   // Inject a UI event into the Cast window.
   virtual void InjectEvent(ui::Event* event) = 0;
+
+  // Register a new handler for a system side swipe event.
+  virtual void AddSideSwipeGestureHandler(
+      CastSideSwipeGestureHandlerInterface* handler) = 0;
+
+  // Remove the registration of a system side swipe event handler.
+  virtual void RemoveSideSwipeGestureHandler(
+      CastSideSwipeGestureHandlerInterface* handler) = 0;
 };
 
 }  // namespace chromecast

chromecast/graphics/cast_window_manager_aura.h

@@ -21,7 +21,6 @@ class ScreenPositionClient;
 namespace chromecast {
 
 class CastFocusClientAura;
-class CastSideSwipeGestureHandlerInterface;
 class CastSystemGestureEventHandler;
 class CastWindowTreeHost;
 
@@ -41,13 +40,11 @@ class CastWindowManagerAura : public CastWindowManager,
   aura::Window* GetDefaultParent(aura::Window* window,
                                  const gfx::Rect& bounds) override;
 
-  // Register a new handler for a system side swipe event.
   void AddSideSwipeGestureHandler(
-      CastSideSwipeGestureHandlerInterface* handler);
+      CastSideSwipeGestureHandlerInterface* handler) override;
 
-  // Remove the registration of a system side swipe event handler.
   void RemoveSideSwipeGestureHandler(
-      CastSideSwipeGestureHandlerInterface* handler);
+      CastSideSwipeGestureHandlerInterface* handler) override;
 
  private:
   friend class CastWindowManager;

chromecast/graphics/cast_window_manager_default.cc

@@ -27,4 +27,12 @@ gfx::NativeView CastWindowManagerDefault::GetRootWindow() {
   return nullptr;
 }
 
+void CastWindowManagerDefault::AddSideSwipeGestureHandler(
+    CastSideSwipeGestureHandlerInterface* handler) {}
+
+// Remove the registration of a system side swipe event handler.
+void CastWindowManagerDefault::CastWindowManagerDefault::
+    RemoveSideSwipeGestureHandler(
+        CastSideSwipeGestureHandlerInterface* handler) {}
+
 }  // namespace chromecast

chromecast/graphics/cast_window_manager_default.h

@@ -23,6 +23,12 @@ class CastWindowManagerDefault : public CastWindowManager {
   gfx::NativeView GetRootWindow() override;
   void InjectEvent(ui::Event* event) override;
 
+  void AddSideSwipeGestureHandler(
+      CastSideSwipeGestureHandlerInterface* handler) override;
+
+  void RemoveSideSwipeGestureHandler(
+      CastSideSwipeGestureHandlerInterface* handler) override;
+
  private:
   friend class CastWindowManager;