[DevUI DFM] Move chrome://media-internals to the DFM

This moves ~19 kB of gzipped resources to the DFM.

The resources are split from content_resources.grd, so extra work is
needed compare to other DevUI DFM page movement tasks:
* Generate media_internals_resources_map.{cc, h}, and have these read by
  SharedResourcesDataSource.
* Repack media_internals_resources.pak into content_shell.pak.

Bug: 927131
Change-Id: Ic10fadb3eff4d519b7eacf430d75e1be3dcba122
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1937850
Reviewed-by: Jochen Eisinger <[email protected]>
Reviewed-by: Andrew Grieve <[email protected]>
Commit-Queue: Samuel Huang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#720210}
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index c3f03cc..5c2b54a 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -95,6 +95,7 @@
     "//content/browser/notifications:notification_proto",
     "//content/browser/payments:payment_app_proto",
     "//content/browser/process_internals:mojo_bindings",
+    "//content/browser/resources/media:media_internals_resources",
     "//content/browser/service_worker:service_worker_proto",
     "//content/browser/speech/proto",
     "//content/browser/webrtc/resources",