Connect new internal repo to an internal directory

We have created a new internal repository found here:
https://chrome-internal.googlesource.com/chrome/browser/resources/downloads_internal/
Now we are mapping the repository to a directory found in c/b/r/downloads/.

The .gitmodules and the c/b/r/downloads/internal (gitlink) files
were autogenerated by running gclient gitmodules. The remaining files
are changes that I manually added.

Bug: 336332581
Change-Id: Ifb6975edd66e369a79fe55eabe39be485cc8c9c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5473544
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Alan Zhao <ayzhao@google.com>
Commit-Queue: Awad Osman <awado@google.com>
Cr-Commit-Position: refs/heads/main@{#1290876}

diff --git a/.gitignore b/.gitignore
index 8a9e1e4..bae3d88 100644
--- a/.gitignore
+++ b/.gitignore

@@ -127,6 +127,7 @@
 /chrome/browser/protector/internal
 /chrome/browser/resources/chromeos/mako/resources/
 /chrome/browser/resources/chromeos/seal/resources/
+/chrome/browser/resources/downloads/internal/
 /chrome/browser/resources/pdf/html_office
 /chrome/browser/resources/media_router/extension/src/
 /chrome/browser/resources/preinstalled_web_apps/internal/