Set guest mode correctly for incognito profiles.

A service factory may check the guest/incognito bits to determine which
context to use.  If these bits aren't set correctly before the various
context-keyed services are created, the result could be the wrong
service, no service, etc.

Without this, apps::LaunchServiceFactory cannot be registered properly
on startup.  (Fixing that will happen separately.)

Bug: none
Change-Id: I75d545066e382a10ff3b5f7aff2db59fa7a6e4c5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2135204
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756310}

chrome/browser/profiles/off_the_record_profile_impl.cc

@@ -40,7 +40,6 @@
 #include "chrome/browser/prefs/incognito_mode_prefs.h"
 #include "chrome/browser/prefs/pref_service_syncable_util.h"
 #include "chrome/browser/profiles/profile_key.h"
-#include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ssl/stateful_ssl_host_state_delegate_factory.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/transition_manager/full_browser_transition_manager.h"
@@ -146,12 +145,13 @@ OffTheRecordProfileImpl::OffTheRecordProfileImpl(
 void OffTheRecordProfileImpl::Init() {
   FullBrowserTransitionManager::Get()->OnProfileCreated(this);
 
+  // Must be done before CreateBrowserContextServices(), since some of them
+  // change behavior based on whether the provided context is a guest session.
+  set_is_guest_profile(profile_->IsGuestSession());
+
   BrowserContextDependencyManager::GetInstance()->CreateBrowserContextServices(
       this);
 
-  set_is_guest_profile(
-      profile_->GetPath() == ProfileManager::GetGuestProfilePath());
-
   // Always crash when incognito is not available.
   // Guest profiles may always be OTR. Check IncognitoModePrefs otherwise.
   CHECK(profile_->IsGuestSession() || profile_->IsSystemProfile() ||

chrome/test/base/testing_profile.cc

@@ -778,8 +778,12 @@ Profile* TestingProfile::GetOffTheRecordProfile(
   DCHECK(otr_profile_id == OTRProfileID::PrimaryID());
   if (IsOffTheRecord())
     return this;
-  if (!incognito_profile_)
-    TestingProfile::Builder().BuildIncognito(this);
+  if (!incognito_profile_) {
+    TestingProfile::Builder builder;
+    if (IsGuestSession())
+      builder.SetGuestSession();
+    builder.BuildIncognito(this);
+  }
   return incognito_profile_.get();
 }