Fix priority of already installed extensions

We assign the priority as FOREGROUND if there is any pending force
installed extension. Then for the enabled/disabled extensions, we set
the priority as FOREGROUND in this case. This causes a  high rate of
"ondemand" updates for certain extensions. This CL fixes this by
assigning FOREGROUND priority only in case of first installs.

Bug: 1133407
Change-Id: I7b6e84e22c240ead798eb6f625ef3c26142c786f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2621893Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Swapnil Gupta <swapnilgupta@google.com>
Cr-Commit-Position: refs/heads/master@{#842601}

chrome/browser/extensions/updater/extension_updater.cc

@@ -371,14 +371,6 @@ void ExtensionUpdater::CheckNow(CheckParams params) {
   ExtensionUpdateCheckParams update_check_params;
 
   if (params.ids.empty()) {
-    // We have to mark high-priority extensions (such as policy-forced
-    // extensions or external component extensions) with foreground fetch
-    // priority; otherwise their installation may be throttled by bandwidth
-    // limits.
-    // See https://crbug.com/904600 and https://crbug.com/965686.
-    if (pending_extension_manager->HasHighPriorityPendingExtension())
-      params.fetch_priority = ManifestFetchData::FOREGROUND;
-
     // If no extension ids are specified, check for updates for all extensions.
     pending_extension_manager->GetPendingIdsForUpdateCheck(&pending_ids);
 
@@ -393,12 +385,22 @@ void ExtensionUpdater::CheckNow(CheckParams params) {
       const bool is_corrupt_reinstall =
           pending_extension_manager->IsPolicyReinstallForCorruptionExpected(
               pending_id);
+      // We have to mark high-priority extensions (such as policy-forced
+      // extensions or external component extensions) with foreground fetch
+      // priority; otherwise their installation may be throttled by bandwidth
+      // limits.
+      // See https://crbug.com/904600 and https://crbug.com/965686.
+      const bool is_high_priority_extension_pending =
+          pending_extension_manager->HasHighPriorityPendingExtension();
       if (CanUseUpdateService(pending_id)) {
         update_check_params.update_info[pending_id].is_corrupt_reinstall =
             is_corrupt_reinstall;
       } else if (downloader_->AddPendingExtension(
                      pending_id, info->update_url(), info->install_source(),
-                     is_corrupt_reinstall, request_id, params.fetch_priority)) {
+                     is_corrupt_reinstall, request_id,
+                     is_high_priority_extension_pending
+                         ? ManifestFetchData::FOREGROUND
+                         : params.fetch_priority)) {
         request.in_progress_ids_.insert(pending_id);
         InstallStageTracker::Get(profile_)->ReportInstallationStage(
             pending_id, InstallStageTracker::Stage::DOWNLOADING);