Replacing allocate bitmap IPC messages with a new Mojo interface.

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"
+          "device::mojom::PowerMonitor",
+          "content::mojom::SharedMemoryAllocator"
         ],
         "plugin": [
           "device::mojom::PowerMonitor"
         ],
         "renderer": [
           "blink::mojom::BackgroundSyncService",
           "blink::mojom::BroadcastChannelProvider",
           "blink::mojom::BudgetService",
           "blink::mojom::Hyphenation",
           "blink::mojom::MimeRegistry",
           "blink::mojom::NotificationService",
           "blink::mojom::OffscreenCanvasCompositorFrameSinkProvider",
           "blink::mojom::OffscreenCanvasSurface",
           "blink::mojom::PermissionService",
           "blink::mojom::ShapeDetection",
           "blink::mojom::WebSocket",
+          "content::mojom::SharedMemoryAllocator",
           "content::mojom::MemoryCoordinatorHandle",
           "content::mojom::ServiceWorkerDispatcherHost",
           "content::mojom::StoragePartitionService",
           "content::mojom::URLLoaderFactory",
           "content::mojom::VideoCaptureHost",
           "device::BatteryMonitor",
           "device::mojom::LightSensor",
           "device::mojom::MotionSensor",
           "device::mojom::OrientationSensor",
           "device::mojom::PowerMonitor",
@@ skipping 52 matching lines @@
           "media::mojom::Renderer",
           "mojom::MediaDevicesDispatcherHost"
         ]
       },
       "requires": {
         "service:content_renderer": [ "browser" ]
       }
     }
   }
 }