office Fallback: Add dialog for falling back to QuickOffice

Add dialog to allow the user to choose what to do next when opening
an office file with the office PWA or Google Docs Editors fails, an
example being when their system is offline. Users can choose to fall
back to QuickOffice, try opening their file again or cancel.

The ability to launch QuickOffice as a fallback was introduced in
https://crrev.com/c/3893192/.

The dialog is behind the upload-office-to-cloud flag.

Bug: b:248409672
Change-Id: I6ed8dbd61921d10d6011345776690746ae426b4a

implemented in a future CL"

Low-Coverage-Reason: "Tests for added functions in file_tasks.cc will be
Change-Id: I6ed8dbd61921d10d6011345776690746ae426b4a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3935482
Reviewed-by: Zain Afzal <[email protected]>
Reviewed-by: Jeremie Boulic <[email protected]>
Commit-Queue: Cassy Chun-Crogan <[email protected]>
Reviewed-by: Dominick Ng <[email protected]>
Reviewed-by: Giovanni Ortuno Urquidi <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1066803}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 314156e..e2bc2b5 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -5265,6 +5265,7 @@
       "//chrome/browser/ui/webui/ash/emoji:mojo_bindings",
       "//chrome/browser/ui/webui/ash/launcher_internals:mojo_bindings",
       "//chrome/browser/ui/webui/ash/manage_mirrorsync:mojo_bindings",
+      "//chrome/browser/ui/webui/ash/office_fallback:mojo_bindings",
       "//chrome/browser/ui/webui/ash/parent_access:mojo_bindings",
       "//chrome/browser/ui/webui/ash/vm:mojo_bindings",
       "//chrome/browser/ui/webui/nearby_share:mojom",