Implement a UI for installing one application for Windows.

This CL takes the Google Update/Omaha UI (https://github.com/google/omaha/tree/master/omaha/ui)
and rewrites to work for this updater.

Several original data structures are kept mostly as they were. The code will need to be
further cleaned up as several edge cases and related TODOs are going to be addressed.

The purpose of this CL includes:
* bringing in most of the UI that is going to be necessary to have for a drop in
replacement of Google Update/Omaha
* figure out what update_client features are needed
* understanding the threading and message loop issues
* understanding some of the i18n issues
* understanding dependencies, including WTL dependencies.

Bug: 1017307
Change-Id: I10a7a103cdad86c049a08b3546df404a6d2e01b6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1876874
Reviewed-by: S. Ganesh <[email protected]>
Reviewed-by: Joshua Pawlicki <[email protected]>
Commit-Queue: Sorin Jianu <[email protected]>
Cr-Commit-Position: refs/heads/master@{#709510}
diff --git a/components/update_client/update_client.h b/components/update_client/update_client.h
index 4b8061c..b9f5b4f4 100644
--- a/components/update_client/update_client.h
+++ b/components/update_client/update_client.h
@@ -299,9 +299,9 @@
       // Sent before the update client does an update check.
       COMPONENT_CHECKING_FOR_UPDATES = 1,
 
-      // Sent when there is a new version of a registered CRX. After
-      // the notification is sent the CRX will be downloaded unless the
-      // update client inserts a
+      // Sent when there is a new version of a registered CRX. The CRX will be
+      // downloaded after the notification unless the update client inserts
+      // a wait because of a throttling policy.
       COMPONENT_UPDATE_FOUND,
 
       // Sent when a CRX is in the update queue but it can't be acted on