Factored out ipcRender.send

Summary: Delegate sending events over IPC from the render process to the main process over the RenderHost interface. This basically removes all our direct usages of `ipcRenderer`.

Reviewed By: timur-valiev, aigoncharov

Differential Revision: D31828580

fbshipit-source-id: 9c1333ae55620d36c2af70aa7abc5403c2f4907c

desktop/app/src/init.tsx

@@ -57,7 +57,7 @@ import {
   GK as flipperCommonGK,
 } from 'flipper-common';
 import {internGraphPOSTAPIRequest} from './fb-stubs/user';
-import {setRenderHostInstance} from './RenderHost';
+import {getRenderHostInstance, setRenderHostInstance} from './RenderHost';
 import {clipboard} from 'electron';
 
 if (process.env.NODE_ENV === 'development' && os.platform() === 'darwin') {
@@ -249,7 +249,7 @@ function init() {
       (
         document.getElementById('flipper-theme-import') as HTMLLinkElement
       ).href = `themes/${result.shouldUseDarkMode ? 'dark' : 'light'}.css`;
-      ipcRenderer.send('setTheme', result.theme);
+      getRenderHostInstance().sendIpcEvent('setTheme', result.theme);
     },
   );
 }
@@ -302,5 +302,8 @@ function initializeFlipperForElectron() {
         callback(...(args as any));
       });
     },
+    sendIpcEvent(event, ...args: any[]) {
+      ipcRenderer.send(event, ...args);
+    },
   });
 }