Fix a browser crash on opening 'chrome://voicesearch' in guest mode.

chrome/browser/search/hotword_service_factory.cc

Index: chrome/browser/search/hotword_service_factory.cc
diff --git a/chrome/browser/search/hotword_service_factory.cc b/chrome/browser/search/hotword_service_factory.cc
index d8a061965324dd2d0c639d501872c3861e660f0e..55b6b15479880038ff8478fd578aa3f93844d878 100644
--- a/chrome/browser/search/hotword_service_factory.cc
+++ b/chrome/browser/search/hotword_service_factory.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/search/hotword_service_factory.h"
 
 #include "base/prefs/pref_service.h"
+#include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/hotword_service.h"
 #include "chrome/common/pref_names.h"
@@ -111,6 +112,11 @@ void HotwordServiceFactory::RegisterProfilePrefs(
                              user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }
 
+content::BrowserContext* HotwordServiceFactory::GetBrowserContextToUse(
+    content::BrowserContext* context) const {
+  return chrome::GetBrowserContextRedirectedInIncognito(context);

[rpetterson, 2014/09/08 17:35:01]

With this change, this will now return the original profile when in Incognito
which will have a valid HotwordService. Even for calls such as
HotwordServiceFactory::GetForProfile. While this is fine for the
about://voicesearch page, it's not fine for the rest of hotwording which relies
on having a NULL service for incognito since hotwording should not be available
then.

I put in a fix to redirect for incognito profiles
(https://codereview.chromium.org/450763002/). Do you know what the difference
between guest mode and incognito mode is such that it doesn't work for guest
mode?

+}
+
 KeyedService* HotwordServiceFactory::BuildServiceInstanceFor(
     BrowserContext* context) const {
   return new HotwordService(Profile::FromBrowserContext(context));