Make Blacklist::IsBlacklist asynchronous (it will need to be for safe

chrome/browser/extensions/blacklist.cc

Index: chrome/browser/extensions/blacklist.cc
diff --git a/chrome/browser/extensions/blacklist.cc b/chrome/browser/extensions/blacklist.cc
index 834d262198118505664203a09d61d53780e5c188..3d745a638559e22bb396c8fbfb1494b02dcdbccc 100644
--- a/chrome/browser/extensions/blacklist.cc
+++ b/chrome/browser/extensions/blacklist.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/browser/extensions/blacklist.h"
 
+#include <algorithm>
+
+#include "base/bind.h"
+#include "base/message_loop.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/common/pref_names.h"
@@ -24,12 +28,18 @@ Blacklist::Blacklist(ExtensionPrefs* prefs) : prefs_(prefs) {
 Blacklist::~Blacklist() {
 }
 
-bool Blacklist::IsBlacklisted(const Extension* extension) const {
-  return prefs_->IsExtensionBlacklisted(extension->id());
-}
-
-bool Blacklist::IsBlacklisted(const std::string& extension_id) const {
-  return prefs_->IsExtensionBlacklisted(extension_id);
+void Blacklist::GetBlacklistedIDs(const std::set<std::string>& ids,
+                                  const GetBlacklistedIDsCallback& callback) {
+  // TODO(kalman): Get the blacklisted IDs from the safebrowsing list.
+  // This will require going to the IO thread and back.
+  std::set<std::string> blacklisted_ids;
+  for (std::set<std::string>::const_iterator it = ids.begin();
+       it != ids.end(); ++it) {
+    if (prefs_->IsExtensionBlacklisted(*it))
+      blacklisted_ids.insert(*it);
+  }
+  MessageLoop::current()->PostTask(FROM_HERE,
+                                   base::Bind(callback, blacklisted_ids));
 }
 
 void Blacklist::SetFromUpdater(const std::vector<std::string>& ids,
@@ -43,7 +53,28 @@ void Blacklist::SetFromUpdater(const std::vector<std::string>& ids,
       LOG(WARNING) << "Got invalid extension ID \"" << *it << "\"";
   }
 
-  prefs_->UpdateBlacklist(ids_as_set);
+  std::set<std::string> from_prefs = prefs_->GetBlacklistedExtensions();
+
+  std::set<std::string> no_longer_blacklisted;
+  std::set_difference(from_prefs.begin(), from_prefs.end(),
+                      ids_as_set.begin(), ids_as_set.end(),
+                      std::inserter(no_longer_blacklisted,
+                                    no_longer_blacklisted.begin()));
+  std::set<std::string> not_yet_blacklisted;
+  std::set_difference(ids_as_set.begin(), ids_as_set.end(),
+                      from_prefs.begin(), from_prefs.end(),
+                      std::inserter(not_yet_blacklisted,
+                                    not_yet_blacklisted.begin()));
+
+  for (std::set<std::string>::iterator it = no_longer_blacklisted.begin();
+       it != no_longer_blacklisted.end(); ++it) {
+    prefs_->SetExtensionBlacklisted(*it, false);
+  }
+  for (std::set<std::string>::iterator it = not_yet_blacklisted.begin();
+       it != not_yet_blacklisted.end(); ++it) {
+    prefs_->SetExtensionBlacklisted(*it, true);
+  }
+
   prefs_->pref_service()->SetString(prefs::kExtensionBlacklistUpdateVersion,
                                     version);