Revert "Fix crash of query tiles internals in incognito mode."

This reverts commit dd04950b.

Reason for revert: Need to hide the query tiles internals WebUI
in Incognito mode. Alternative CL:
https://chromium-review.googlesource.com/c/chromium/src/+/2327374

Original change's description:
> Fix crash of query tiles internals in incognito mode.
>
> - TileService not support incognito profile.
>
> Bug: 1110285
> Change-Id: Ief1c8025b74ec5df94c5e811d213a6679fd6069c
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2324938
> Reviewed-by: Min Qin <qinmin@chromium.org>
> Commit-Queue: Hesen Zhang <hesen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#792500}

TBR=dtrainor@chromium.org,qinmin@chromium.org,hesen@chromium.org

Change-Id: I7126c77cc412de10f9a6af2495d408dd7153fc1f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1110285
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2327313
Commit-Queue: Hesen Zhang <hesen@chromium.org>
Reviewed-by: Hesen Zhang <hesen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792827}

chrome/browser/ui/webui/internals/query_tiles/query_tiles_internals_ui_message_handler.cc

@@ -19,7 +19,9 @@
 QueryTilesInternalsUIMessageHandler::QueryTilesInternalsUIMessageHandler(
     Profile* profile)
     : tile_service_(query_tiles::TileServiceFactory::GetForKey(
-          profile->GetProfileKey())) {}
+          profile->GetProfileKey())) {
+  DCHECK(tile_service_);
+}
 
 QueryTilesInternalsUIMessageHandler::~QueryTilesInternalsUIMessageHandler() =
     default;
@@ -52,8 +54,6 @@ void QueryTilesInternalsUIMessageHandler::RegisterMessages() {
 
 void QueryTilesInternalsUIMessageHandler::HandleGetTileData(
     const base::ListValue* args) {
-  if (!tile_service_)
-    return;
   AllowJavascript();
   const base::Value* callback_id;
   auto result = args->Get(0, &callback_id);
@@ -64,8 +64,6 @@ void QueryTilesInternalsUIMessageHandler::HandleGetTileData(
 
 void QueryTilesInternalsUIMessageHandler::HandleGetServiceStatus(
     const base::ListValue* args) {
-  if (!tile_service_)
-    return;
   AllowJavascript();
   const base::Value* callback_id;
   auto result = args->Get(0, &callback_id);
@@ -76,8 +74,6 @@ void QueryTilesInternalsUIMessageHandler::HandleGetServiceStatus(
 
 void QueryTilesInternalsUIMessageHandler::HandleStartFetch(
     const base::ListValue* args) {
-  if (!tile_service_)
-    return;
   AllowJavascript();
   tile_service_->StartFetchForTiles(false /*is_from_reduce_mode*/,
                                     base::BindOnce([](bool reschedule) {}));
@@ -85,14 +81,11 @@ void QueryTilesInternalsUIMessageHandler::HandleStartFetch(
 
 void QueryTilesInternalsUIMessageHandler::HandlePurgeDb(
     const base::ListValue* args) {
-  if (tile_service_)
-    tile_service_->PurgeDb();
+  tile_service_->PurgeDb();
 }
 
 void QueryTilesInternalsUIMessageHandler::HandleSetServerUrl(
     const base::ListValue* args) {
-  if (!tile_service_)
-    return;
   AllowJavascript();
   DCHECK_EQ(args->GetList().size(), 1u) << "Missing argument server URL.";
   tile_service_->SetServerUrl(args->GetList()[0].GetString());
@@ -109,8 +102,7 @@ void QueryTilesInternalsUIMessageHandler::OnTileDataAvailable(
 }
 
 void QueryTilesInternalsUIMessageHandler::OnJavascriptAllowed() {
-  if (tile_service_)
-    logger_observer_.Add(tile_service_->GetLogger());
+  logger_observer_.Add(tile_service_->GetLogger());
 }
 
 void QueryTilesInternalsUIMessageHandler::OnJavascriptDisallowed() {