Added automatic update for plugins based on watching file changes.

BUG=48383
TEST=Add or remove some files to a default plugin location and check in about:plugins whether the change got detected. Also part of integration tests.

Review URL: http://codereview.chromium.org/6163003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71783 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 93 insertions, 12 deletions

diff --git a/chrome/browser/plugin_service.cc b/chrome/browser/plugin_service.cc
index cadc7e2..e136f97c 100644
--- a/chrome/browser/plugin_service.cc
+++ b/chrome/browser/plugin_service.cc
@@ -56,6 +56,29 @@ static void NotifyPluginsOfActivation() {
 }
 #endif
 
+static void PurgePluginListCache(bool reload_pages) {
+  for (RenderProcessHost::iterator it = RenderProcessHost::AllHostsIterator();
+       !it.IsAtEnd(); it.Advance()) {
+    it.GetCurrentValue()->Send(new ViewMsg_PurgePluginListCache(reload_pages));
+  }
+}
+
+#if defined(OS_LINUX)
+// Delegate class for monitoring directories.
+class PluginDirWatcherDelegate : public FilePathWatcher::Delegate {
+  virtual void OnFilePathChanged(const FilePath& path) {
+    VLOG(1) << "Watched path changed: " << path.value();
+    // Make the plugin list update itself
+    webkit::npapi::PluginList::Singleton()->RefreshPlugins();
+  }
+  virtual void OnError() {
+    // TODO(pastarmovj): Add some sensible error handling. Maybe silently
+    // stopping the watcher would be enough. Or possibly restart it.
+    NOTREACHED();
+  }
+};
+#endif
+
 // static
 bool PluginService::enable_chrome_plugins_ = true;
 
@@ -120,6 +143,9 @@ PluginService::PluginService()
 
   chrome::RegisterInternalGPUPlugin();
 
+  // Start watching for changes in the plugin list. This means watching
+  // for changes in the Windows registry keys and on both Windows and POSIX
+  // watch for changes in the paths that are expected to contain plugins.
 #if defined(OS_WIN)
   hkcu_key_.Create(
       HKEY_CURRENT_USER, webkit::npapi::kRegistryMozillaPlugins, KEY_NOTIFY);
@@ -143,7 +169,36 @@ PluginService::PluginService()
         user_data_dir.Append("Plugins"));
   }
 #endif
-
+// The FilePathWatcher produces too many false positives on MacOS (access time
+// updates?) which will lead to enforcing updates of the plugins way too often.
+// On ChromeOS the user can't install plugins anyway and on Windows all
+// important plugins register themselves in the registry so no need to do that.
+#if defined(OS_LINUX)
+  file_watcher_delegate_ = new PluginDirWatcherDelegate();
+  // Get the list of all paths for registering the FilePathWatchers
+  // that will track and if needed reload the list of plugins on runtime.
+  std::vector<FilePath> plugin_dirs;
+  webkit::npapi::PluginList::Singleton()->GetPluginDirectories(
+      &plugin_dirs);
+
+  for (size_t i = 0; i < plugin_dirs.size(); ++i) {
+    FilePathWatcher* watcher = new FilePathWatcher();
+    // FilePathWatcher can not handle non-absolute paths under windows.
+    // We don't watch for file changes in windows now but if this should ever
+    // be extended to Windows these lines might save some time of debugging.
+#if defined(OS_WIN)
+    if (!plugin_dirs[i].IsAbsolute())
+      continue;
+#endif
+    VLOG(1) << "Watching for changes in: " << plugin_dirs[i].value();
+    BrowserThread::PostTask(
+        BrowserThread::FILE, FROM_HERE,
+        NewRunnableFunction(
+            &PluginService::RegisterFilePathWatcher,
+            watcher, plugin_dirs[i], file_watcher_delegate_));
+    file_watchers_.push_back(watcher);
+  }
+#endif
   registrar_.Add(this, NotificationType::EXTENSION_LOADED,
                  NotificationService::AllSources());
   registrar_.Add(this, NotificationType::EXTENSION_UNLOADED,
@@ -302,13 +357,6 @@ bool PluginService::GetFirstAllowedPluginInfo(
 #endif
 }
 
-static void PurgePluginListCache(bool reload_pages) {
-  for (RenderProcessHost::iterator it = RenderProcessHost::AllHostsIterator();
-       !it.IsAtEnd(); it.Advance()) {
-    it.GetCurrentValue()->Send(new ViewMsg_PurgePluginListCache(reload_pages));
-  }
-}
-
 void PluginService::OnWaitableEventSignaled(
     base::WaitableEvent* waitable_event) {
 #if defined(OS_WIN)
@@ -320,6 +368,9 @@ void PluginService::OnWaitableEventSignaled(
 
   webkit::npapi::PluginList::Singleton()->RefreshPlugins();
   PurgePluginListCache(true);
+#else
+  // This event should only get signaled on a Windows machine.
+  NOTREACHED();
 #endif  // defined(OS_WIN)
 }
 
@@ -384,7 +435,7 @@ void PluginService::Observe(NotificationType type,
       break;
     }
     default:
-      DCHECK(false);
+      NOTREACHED();
   }
 }
 
@@ -426,3 +477,14 @@ void PluginService::RegisterPepperPlugins() {
     webkit::npapi::PluginList::Singleton()->RegisterInternalPlugin(info);
   }
 }
+
+#if defined(OS_LINUX)
+// static
+void PluginService::RegisterFilePathWatcher(
+    FilePathWatcher *watcher,
+    const FilePath& path,
+    FilePathWatcher::Delegate* delegate) {
+  bool result = watcher->Watch(path, delegate);
+  DCHECK(result);
+}
+#endif
diff --git a/chrome/browser/plugin_service.h b/chrome/browser/plugin_service.h
index e90f6a7..5e03c09 100644
--- a/chrome/browser/plugin_service.h
+++ b/chrome/browser/plugin_service.h
@@ -14,6 +14,7 @@
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/hash_tables.h"
+#include "base/scoped_vector.h"
 #include "base/singleton.h"
 #include "base/synchronization/waitable_event_watcher.h"
 #include "build/build_config.h"
@@ -28,6 +29,10 @@
 #include "base/win/registry.h"
 #endif
 
+#if defined(OS_LINUX)
+#include "chrome/browser/file_path_watcher/file_path_watcher.h"
+#endif
+
 #if defined(OS_CHROMEOS)
 namespace chromeos {
 class PluginSelectionPolicy;
@@ -40,6 +45,7 @@ class Message;
 
 class MessageLoop;
 class Profile;
+class PluginDirWatcherDelegate;
 class ResourceDispatcherHost;
 
 namespace net {
@@ -144,6 +150,14 @@ class PluginService
       const FilePath& plugin_path,
       PluginProcessHost::Client* client);
 
+#if defined(OS_LINUX)
+  // Registers a new FilePathWatcher for a given path.
+  static void RegisterFilePathWatcher(
+      FilePathWatcher* watcher,
+      const FilePath& path,
+      FilePathWatcher::Delegate* delegate);
+#endif
+
   // mapping between plugin path and PluginProcessHost
   typedef base::hash_map<FilePath, PluginProcessHost*> PluginMap;
   PluginMap plugin_hosts_;
@@ -181,6 +195,11 @@ class PluginService
   base::WaitableEventWatcher hklm_watcher_;
 #endif
 
+#if defined(OS_LINUX)
+  ScopedVector<FilePathWatcher> file_watchers_;
+  scoped_refptr<PluginDirWatcherDelegate> file_watcher_delegate_;
+#endif
+
   // Set to true if chrome plugins are enabled. Defaults to true.
   static bool enable_chrome_plugins_;
 
diff --git a/webkit/plugins/npapi/plugin_list.h b/webkit/plugins/npapi/plugin_list.h
index 553b554..84026eb 100644
--- a/webkit/plugins/npapi/plugin_list.h
+++ b/webkit/plugins/npapi/plugin_list.h
@@ -97,6 +97,9 @@ class PluginList {
   // Same as above, but specifies a directory in which to search for plugins.
   void AddExtraPluginDir(const FilePath& plugin_dir);
 
+  // Get the ordered list of directories from which to load plugins
+  void GetPluginDirectories(std::vector<FilePath>* plugin_dirs);
+
   // Register an internal plugin with the specified plugin information and
   // function pointers.  An internal plugin must be registered before it can
   // be loaded using PluginList::LoadPlugin().
@@ -283,9 +286,6 @@ class PluginList {
   // Do any initialization.
   void PlatformInit();
 
-  // Get the ordered list of directories from which to load plugins
-  void GetPluginDirectories(std::vector<FilePath>* plugin_dirs);
-
   //
   // Command-line switches
   //