Mojo C++ bindings: support mapping T and T? differently.

components/arc/test/fake_app_instance.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 COMPONENTS_ARC_TEST_FAKE_APP_INSTANCE_H_
 #define COMPONENTS_ARC_TEST_FAKE_APP_INSTANCE_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 67 matching lines @@
   };
 
   explicit FakeAppInstance(mojom::AppHost* app_host);
   ~FakeAppInstance() override;
 
   // mojom::AppInstance overrides:
   void Init(mojom::AppHostPtr host_ptr) override {}
   void RefreshAppList() override;
   void LaunchApp(const mojo::String& package_name,
                  const mojo::String& activity,
-                 const gfx::Rect& dimension) override;
+                 const base::Optional<gfx::Rect>& dimension) override;
   void RequestAppIcon(const mojo::String& package_name,
                       const mojo::String& activity,
                       mojom::ScaleFactor scale_factor) override;
-  void LaunchIntent(const mojo::String& intent_uri,
-                    const gfx::Rect& dimension_on_screen) override;
+  void LaunchIntent(
+      const mojo::String& intent_uri,
+      const base::Optional<gfx::Rect>& dimension_on_screen) override;
   void RequestIcon(const mojo::String& icon_resource_id,
                    arc::mojom::ScaleFactor scale_factor,
                    const RequestIconCallback& callback) override;
   void RemoveCachedIcon(const mojo::String& icon_resource_id) override;
   void CanHandleResolution(
       const mojo::String& package_name,
       const mojo::String& activity,
       const gfx::Rect& dimension,
       const CanHandleResolutionCallback& callback) override;
   void UninstallPackage(const mojo::String& package_name) override;
@@ skipping 64 matching lines @@
 
   bool GetFakeIcon(mojom::ScaleFactor scale_factor,
                    std::string* png_data_as_string);
 
   DISALLOW_COPY_AND_ASSIGN(FakeAppInstance);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_TEST_FAKE_APP_INSTANCE_H_