Web MIDI: add RequestMIDISysExPermission to BrowserContext

android_webview/browser/aw_browser_context.cc

Index: android_webview/browser/aw_browser_context.cc
diff --git a/android_webview/browser/aw_browser_context.cc b/android_webview/browser/aw_browser_context.cc
index 02fd0c3df91a1459b0f86f4888c7d3dcdb2c8ce3..a1008e646e103fec06074291c0ea2055b703fe7e 100644
--- a/android_webview/browser/aw_browser_context.cc
+++ b/android_webview/browser/aw_browser_context.cc
@@ -180,6 +180,16 @@ net::URLRequestContextGetter* AwBrowserContext::GetMediaRequestContext() {
   return GetRequestContext();
 }
 
+void AwBrowserContext::RequestMIDISysExPermission(
+      int render_process_id,
+      int render_view_id,
+      int client_id,
+      const GURL& requesting_frame,
+      const MIDISysExPermissionCallback& callback) {
+  // Always reject requests for testing.
+  callback.Run(render_process_id, render_view_id, client_id, false);
+}
+
 net::URLRequestContextGetter*
 AwBrowserContext::GetMediaRequestContextForRenderProcess(
     int renderer_child_id) {