Publish the location of the screensaver extension from the AppPackUpdater.

BUG=chromium-os:25463,chromium-os:23178
TEST=Set the AppPack and ScreenSaver policies. The ScreenSaver extension is downloaded but not installed.


Review URL: http://codereview.chromium.org/9753006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@127743 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 60 insertions, 6 deletions

diff --git a/chrome/browser/policy/app_pack_updater.cc b/chrome/browser/policy/app_pack_updater.cc
index 7556f3a..f06f0a9 100644
--- a/chrome/browser/policy/app_pack_updater.cc
+++ b/chrome/browser/policy/app_pack_updater.cc
@@ -5,7 +5,6 @@
 #include "chrome/browser/policy/app_pack_updater.h"
 
 #include "base/bind.h"
-#include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/location.h"
 #include "base/stl_util.h"
@@ -116,6 +115,16 @@ ExternalExtensionLoader* AppPackUpdater::CreateExternalExtensionLoader() {
   return loader;
 }
 
+void AppPackUpdater::SetScreenSaverUpdateCallback(
+    const AppPackUpdater::ScreenSaverUpdateCallback& callback) {
+  screen_saver_update_callback_ = callback;
+  if (!screen_saver_update_callback_.is_null() && !screen_saver_path_.empty()) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(screen_saver_update_callback_, screen_saver_path_));
+  }
+}
+
 void AppPackUpdater::Init() {
   worker_pool_token_ = BrowserThread::GetBlockingPool()->GetSequenceToken();
   chromeos::CrosSettings::Get()->AddSettingsObserver(chromeos::kAppPack, this);
@@ -147,6 +156,7 @@ void AppPackUpdater::LoadPolicy() {
                      weak_ptr_factory_.GetWeakPtr()))) {
     return;
   }
+
   app_pack_extensions_.clear();
   const base::Value* value = settings->GetPref(chromeos::kAppPack);
   const base::ListValue* list = NULL;
@@ -173,6 +183,12 @@ void AppPackUpdater::LoadPolicy() {
   VLOG(1) << "Refreshed AppPack policy, got " << app_pack_extensions_.size()
           << " entries.";
 
+  value = settings->GetPref(chromeos::kScreenSaverExtensionId);
+  if (!value || !value->GetAsString(&screen_saver_id_)) {
+    screen_saver_id_.clear();
+    SetScreenSaverPath(FilePath());
+  }
+
   CheckCacheNow();
 }
 
@@ -450,12 +466,17 @@ void AppPackUpdater::OnCacheEntryInstalled(const std::string& id,
                                            const std::string& path,
                                            const std::string& version) {
   VLOG(1) << "AppPack installed a new extension in the cache: " << path;
-  // AppPack +1
-  CacheEntry& entry = cached_extensions_[id];
-  entry.path = path;
-  entry.cached_version = version;
 
-  UpdateExtensionLoader();
+  if (id == screen_saver_id_) {
+    VLOG(1) << "AppPack got the screen saver extension at " << path;
+    SetScreenSaverPath(FilePath(path));
+  } else {
+    // Add to the list of cached extensions.
+    CacheEntry& entry = cached_extensions_[id];
+    entry.path = path;
+    entry.cached_version = version;
+    UpdateExtensionLoader();
+  }
 }
 
 void AppPackUpdater::PostBlockingTask(const tracked_objects::Location& location,
@@ -465,4 +486,13 @@ void AppPackUpdater::PostBlockingTask(const tracked_objects::Location& location,
       base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
 }
 
+void AppPackUpdater::SetScreenSaverPath(const FilePath& path) {
+  // Don't invoke the callback if the path isn't changing.
+  if (path != screen_saver_path_) {
+    screen_saver_path_ = path;
+    if (!screen_saver_update_callback_.is_null())
+      screen_saver_update_callback_.Run(screen_saver_path_);
+  }
+}
+
 }  // namespace policy
diff --git a/chrome/browser/policy/app_pack_updater.h b/chrome/browser/policy/app_pack_updater.h
index bda82b0..1fedbe9 100644
--- a/chrome/browser/policy/app_pack_updater.h
+++ b/chrome/browser/policy/app_pack_updater.h
@@ -11,7 +11,9 @@
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/callback.h"
 #include "base/compiler_specific.h"
+#include "base/file_path.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/extensions/updater/extension_downloader_delegate.h"
@@ -46,6 +48,9 @@ class AppPackUpdater : public CloudPolicySubsystem::Observer,
                        public content::NotificationObserver,
                        public extensions::ExtensionDownloaderDelegate {
  public:
+  // Callback to listen for updates to the screensaver extension's path.
+  typedef base::Callback<void(const FilePath&)> ScreenSaverUpdateCallback;
+
   // Keys for the entries in the AppPack dictionary policy.
   static const char kExtensionId[];
   static const char kUpdateUrl[];
@@ -60,6 +65,12 @@ class AppPackUpdater : public CloudPolicySubsystem::Observer,
   // owns the returned value.
   ExternalExtensionLoader* CreateExternalExtensionLoader();
 
+  // |callback| will be invoked whenever the screen saver extension's path
+  // changes. It will be invoked "soon" after this call if a valid path already
+  // exists. Subsequent calls will override the previous |callback|. A null
+  // |callback| can be used to remove a previous callback.
+  void SetScreenSaverUpdateCallback(const ScreenSaverUpdateCallback& callback);
+
  private:
   struct CacheEntry {
     std::string path;
@@ -156,6 +167,10 @@ class AppPackUpdater : public CloudPolicySubsystem::Observer,
   void PostBlockingTask(const tracked_objects::Location& from_here,
                         const base::Closure& task);
 
+  // Sets |screen_saver_path_| and invokes |screen_saver_update_callback_| if
+  // appropriate.
+  void SetScreenSaverPath(const FilePath& path);
+
   base::WeakPtrFactory<AppPackUpdater> weak_ptr_factory_;
 
   // Observes updates to the |device_cloud_policy_subsystem_|, to detect
@@ -173,6 +188,15 @@ class AppPackUpdater : public CloudPolicySubsystem::Observer,
   // and that have a valid crx in the cache.
   CacheEntryMap cached_extensions_;
 
+  // The extension ID and path of the CRX file of the screen saver extension,
+  // if it is configured by the policy. Otherwise these fields are empty.
+  std::string screen_saver_id_;
+  FilePath screen_saver_path_;
+
+  // Callback to invoke whenever the screen saver's extension path changes.
+  // Can be null.
+  ScreenSaverUpdateCallback screen_saver_update_callback_;
+
   // The extension loader wires the AppPackUpdater to the extensions system, and
   // makes it install the currently cached extensions.
   bool created_extension_loader_;