Add "use-winrt-midi-api" flag to enable WinRT WebMIDI backend

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 8a2e7759b66ddbbd81a9a7fa50d71611451908c8..e02d85a67b738ba3273bd75e69b3128ac8820161 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -14827,6 +14827,12 @@ Please check your email at <ph name="ACCOUNT_EMAIL">$2<ex>jane.doe@gmail.com</ex
       <message name="IDS_FLAGS_MERGE_KEY_CHAR_EVENTS_DESCRIPTION" desc="Description for the flag to enable/disable merging the key event with char event.">
         If disabled, Chrome will handle WM_KEY* and WM_CHAR separatedly.
       </message>
+      <message name="IDS_FLAGS_USE_WINRT_MIDI_API_NAME" desc="Name for the flag to use Windows Runtime MIDI API.">
+        Use Windows Runtime MIDI API
+      </message>
+      <message name="IDS_FLAGS_USE_WINRT_MIDI_API_DESCRIPTION" desc="Description for the flag to use Windows Runtime MIDI API.">
+        Use Windows Runtime MIDI API for WebMIDI (effective only on Windows 10 or later).
+      </message>
     </if>
 
     <if expr="not is_ios">