[Extensions] Obliterating the inline install API.

Removing everything associated with inline installation as it is
deprecated per the announcement in https://blog.chromium.org/2018/06/improving-extension-transparency-for.html

Bug: 882045
Change-Id: Ia24cb4076a841d9b37febe68cad89db7ea1ce1c8
Reviewed-on: https://chromium-review.googlesource.com/c/1220299
Reviewed-by: Scott Violet <[email protected]>
Reviewed-by: Chris Palmer <[email protected]>
Reviewed-by: Devlin <[email protected]>
Commit-Queue: Benjamin Ackerman <[email protected]>
Cr-Commit-Position: refs/heads/master@{#596334}
diff --git a/chrome/browser/extensions/webstore_installer.h b/chrome/browser/extensions/webstore_installer.h
index ce7e85f..2dc86e3a 100644
--- a/chrome/browser/extensions/webstore_installer.h
+++ b/chrome/browser/extensions/webstore_installer.h
@@ -58,6 +58,9 @@
   enum InstallSource {
     // Inline installs trigger slightly different behavior (install source
     // is different, download referrers are the item's page in the gallery).
+    // TODO(ackermanb): Remove once server side metrics (omaha) tracking with
+    // this enum is figured out with any of the subclasses of
+    // WebstoreStandaloneInstaller.
     INSTALL_SOURCE_INLINE,
     INSTALL_SOURCE_APP_LAUNCHER,
     INSTALL_SOURCE_OTHER