PaymentApp: Initial implementation for PaymentAppManager.setManifest().

content/public/app/mojo/content_browser_manifest.json

 {
   "name": "service:content_browser",
   "display_name": "Content (browser process)",
   "interface_provider_specs": {
     "service_manager:connector": {
       "provides": {
         "gpu": [
           "device::mojom::PowerMonitor"
         ],
         "plugin": [
@@ skipping 16 matching lines @@
           "content::mojom::StoragePartitionService",
           "content::mojom::URLLoaderFactory",
           "content::mojom::VideoCaptureHost",
           "device::BatteryMonitor",
           "device::mojom::LightSensor",
           "device::mojom::MotionSensor",
           "device::mojom::OrientationSensor",
           "device::mojom::PowerMonitor",
           "device::mojom::TimeZoneMonitor",
           "media::mojom::ImageCapture",
-          "memory_coordinator::mojom::MemoryCoordinatorHandle"
+          "memory_coordinator::mojom::MemoryCoordinatorHandle",
+          "payments::mojom::PaymentAppManager"
         ],
         "service_manager:service_factory": [
           "service_manager::mojom::ServiceFactory"
         ]
       },
       "requires": {
         "*": [ "app" ],
         // In classic ash, the browser supplies ash interfaces to itself.
         "service:content_browser": [ "ash" ],
         "service:content_gpu": [ "browser" ],
@@ skipping 38 matching lines @@
           "media::mojom::RemoterFactory",
           "mojom::MediaDevicesDispatcherHost"
         ]
       },
       "requires": {
         "service:content_renderer": [ "browser" ]
       }
     }
   }
 }