Componentize safe_browsing: factor out chrome/ deps in ThreatDetailsRedirectsCollector.

chrome/browser/safe_browsing/threat_details.cc

Index: chrome/browser/safe_browsing/threat_details.cc
diff --git a/chrome/browser/safe_browsing/threat_details.cc b/chrome/browser/safe_browsing/threat_details.cc
index 27929cb652df7664d90101349be13cadab9cc6b7..d5b8467d14a5c89fe827fc32740d03c851a4ce2b 100644
--- a/chrome/browser/safe_browsing/threat_details.cc
+++ b/chrome/browser/safe_browsing/threat_details.cc
@@ -15,9 +15,11 @@
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
+#include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/safe_browsing/threat_details_cache.h"
 #include "chrome/browser/safe_browsing/threat_details_history.h"
+#include "components/history/core/browser/history_service.h"
 #include "components/safe_browsing/common/safebrowsing_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_controller.h"
@@ -179,8 +181,13 @@ ThreatDetails::ThreatDetails(BaseUIManager* ui_manager,
       did_proceed_(false),
       num_visits_(0),
       ambiguous_dom_(false),
-      cache_collector_(new ThreatDetailsCacheCollector),
-      redirects_collector_(new ThreatDetailsRedirectsCollector(profile_)) {
+      cache_collector_(new ThreatDetailsCacheCollector) {
+  history::HistoryService* history_service =
+      HistoryServiceFactory::GetForProfile(profile_,
+                                           ServiceAccessType::EXPLICIT_ACCESS);
+  redirects_collector_ = new ThreatDetailsRedirectsCollector(

[Jialiu Lin, 2017/04/05 18:19:47]

If history_service is not available, maybe we don't need to create
ThreatDetailsRedirectsCollector at all.
How about 
 redirects_collector_ = history_service ?
     new ThreatDetailsRedirectsCollector(                    
         history_service->AsWeakPtr()) : nullptr;


And every time redirects_collector_ is called, do a check first.

[timvolodine, 2017/04/06 14:15:23]

Yes that would seem reasonable, because the redirects_collector_ doesn't do much
when there is no history_service. However simply checking for
redirects_collector != null does not seem sufficient as its callback is used for
further starting cache collection (in OnRedirectionCollectionReady, so this
would need more refactoring of the code. Maybe something for a separate patch..

+      history_service ? history_service->AsWeakPtr()
+                      : base::WeakPtr<history::HistoryService>());
   StartCollection();
 }