Allow Flash (and other plugins) to be installed without restarting the browser. This works by monitoring the MozillaPlugins registry key and reloading the plugin list afterwards.

Note: I'll commit the WebKit change separately, but putting it in this change right now so everything can be reviewed together.

BUG=10574
Review URL: http://codereview.chromium.org/88020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@14377 0039d316-1c4b-4281-b951-d872f2087c98

base/registry.cc

@@ -351,8 +351,9 @@ bool RegKey::DeleteValue(const tchar * value_name) {
 }
 
 bool RegKey::StartWatching() {
-  assert(watch_event_ == 0);
-  watch_event_ = CreateEvent(NULL, TRUE, FALSE, NULL);
+  if (!watch_event_)
+    watch_event_ = CreateEvent(NULL, TRUE, FALSE, NULL);
+
   DWORD filter = REG_NOTIFY_CHANGE_NAME |
                  REG_NOTIFY_CHANGE_ATTRIBUTES |
                  REG_NOTIFY_CHANGE_LAST_SET |
@@ -382,10 +383,6 @@ bool RegKey::StopWatching() {
 bool RegKey::HasChanged() {
   if (watch_event_) {
     if (WaitForSingleObject(watch_event_, 0) == WAIT_OBJECT_0) {
-      // An event only gets signaled once, then it's done, so we have
-      // to set up another event to watch.
-      CloseHandle(watch_event_);
-      watch_event_ = 0;
       StartWatching();
       return true;
     }

base/registry.h

@@ -88,6 +88,7 @@ class RegKey {
   bool StopWatching();
 
   inline bool IsWatching() const { return watch_event_ != 0; }
+  HANDLE watch_event() const { return watch_event_; }
   HKEY Handle() const { return key_; }
 
  private:

chrome/browser/plugin_service.cc

@@ -8,15 +8,17 @@
 
 #include "base/command_line.h"
 #include "base/thread.h"
+#include "base/waitable_event.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_plugin_host.h"
 #include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/plugin_process_host.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
-#include "chrome/browser/renderer_host/resource_message_filter.h"
 #include "chrome/common/chrome_plugin_lib.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
+#include "chrome/common/render_messages.h"
+#include "webkit/glue/plugins/plugin_constants_win.h"
 #include "webkit/glue/plugins/plugin_list.h"
 
 // static
@@ -35,9 +37,32 @@ PluginService::PluginService()
   std::wstring path = command_line->GetSwitchValue(switches::kLoadPlugin);
   if (!path.empty())
     NPAPI::PluginList::AddExtraPluginPath(FilePath::FromWStringHack(path));
+
+#if defined(OS_WIN)
+  hkcu_key_.Create(
+      HKEY_CURRENT_USER, kRegistryMozillaPlugins, KEY_NOTIFY);
+  hklm_key_.Create(
+      HKEY_LOCAL_MACHINE, kRegistryMozillaPlugins, KEY_NOTIFY);
+  if (hkcu_key_.StartWatching()) {
+    hkcu_event_.reset(new base::WaitableEvent(hkcu_key_.watch_event()));
+    hkcu_watcher_.StartWatching(hkcu_event_.get(), this);
+  }
+
+  if (hklm_key_.StartWatching()) {
+    hklm_event_.reset(new base::WaitableEvent(hklm_key_.watch_event()));
+    hklm_watcher_.StartWatching(hklm_event_.get(), this);
+  }
+#endif
 }
 
 PluginService::~PluginService() {
+#if defined(OS_WIN)
+  // Release the events since they're owned by RegKey, not WaitableEvent.
+  hkcu_watcher_.StopWatching();
+  hklm_watcher_.StopWatching();
+  hkcu_event_->Release();
+  hklm_event_->Release();
+#endif
 }
 
 void PluginService::GetPlugins(bool refresh,
@@ -171,3 +196,21 @@ bool PluginService::HavePluginFor(const std::string& mime_type,
                                                        allow_wildcard, &info,
                                                        NULL);
 }
+
+void PluginService::OnWaitableEventSignaled(base::WaitableEvent* waitable_event) {
+#if defined(OS_WIN)
+  if (waitable_event == hkcu_event_.get()) {
+    hkcu_key_.StartWatching();
+  } else {
+    hklm_key_.StartWatching();
+  }
+
+  AutoLock lock(lock_);
+  NPAPI::PluginList::ResetPluginsLoaded();
+
+  for (RenderProcessHost::iterator it = RenderProcessHost::begin();
+       it != RenderProcessHost::end(); ++it) {
+    it->second->Send(new ViewMsg_PurgePluginListCache());
+  }
+#endif
+}

chrome/browser/plugin_service.h

@@ -15,9 +15,14 @@
 #include "base/lock.h"
 #include "base/ref_counted.h"
 #include "base/singleton.h"
+#include "base/waitable_event_watcher.h"
 #include "chrome/browser/browser_process.h"
 #include "webkit/glue/webplugin.h"
 
+#if defined(OS_WIN)
+#include "base/registry.h"
+#endif
+
 namespace IPC {
 class Message;
 }
@@ -30,7 +35,7 @@ class ResourceMessageFilter;
 
 // This can be called on the main thread and IO thread.  However it must
 // be created on the main thread.
-class PluginService {
+class PluginService : base::WaitableEventWatcher::Delegate {
  public:
   // Returns the PluginService singleton.
   static PluginService* GetInstance();
@@ -109,6 +114,9 @@ class PluginService {
   PluginService();
   ~PluginService();
 
+  // base::WaitableEventWatcher::Delegate implementation.
+  void OnWaitableEventSignaled(base::WaitableEvent* waitable_event);
+
   // mapping between plugin path and PluginProcessHost
   typedef base::hash_map<FilePath, PluginProcessHost*> PluginMap;
   PluginMap plugin_hosts_;
@@ -129,6 +137,16 @@ class PluginService {
   // webkit_glue since this class is called on the main and IO thread.
   Lock lock_;
 
+#if defined(OS_WIN)
+  // Registry keys for getting notifications when new plugins are installed.
+  RegKey hkcu_key_;
+  RegKey hklm_key_;
+  scoped_ptr<base::WaitableEvent> hkcu_event_;
+  scoped_ptr<base::WaitableEvent> hklm_event_;
+  base::WaitableEventWatcher hkcu_watcher_;
+  base::WaitableEventWatcher hklm_watcher_;
+#endif
+
   DISALLOW_COPY_AND_ASSIGN(PluginService);
 };
 

chrome/common/render_messages_internal.h

@@ -382,6 +382,9 @@ IPC_BEGIN_MESSAGES(View)
   // Install the first missing pluign.
   IPC_MESSAGE_ROUTED0(ViewMsg_InstallMissingPlugin)
 
+  // Tells the renderer to empty its plugin list cache.
+  IPC_MESSAGE_CONTROL0(ViewMsg_PurgePluginListCache)
+
   IPC_MESSAGE_ROUTED1(ViewMsg_RunFileChooserResponse,
                       std::vector<FilePath> /* selected files */)
 

chrome/renderer/render_thread.cc

@@ -62,13 +62,15 @@ static const unsigned int kCacheStatsDelayMS = 2000 /* milliseconds */;
 RenderThread::RenderThread()
     : ChildThread(
           base::Thread::Options(RenderProcess::InProcessPlugins() ?
-              MessageLoop::TYPE_UI : MessageLoop::TYPE_DEFAULT, kV8StackSize)) {
+              MessageLoop::TYPE_UI : MessageLoop::TYPE_DEFAULT, kV8StackSize)),
+      plugin_refresh_allowed_(true) {
 }
 
 RenderThread::RenderThread(const std::wstring& channel_name)
     : ChildThread(
           base::Thread::Options(RenderProcess::InProcessPlugins() ?
-              MessageLoop::TYPE_UI : MessageLoop::TYPE_DEFAULT, kV8StackSize)) {
+              MessageLoop::TYPE_UI : MessageLoop::TYPE_DEFAULT, kV8StackSize)),
+      plugin_refresh_allowed_(true) {
   SetChannelName(channel_name);
 }
 
@@ -197,6 +199,8 @@ void RenderThread::OnControlMessageReceived(const IPC::Message& msg) {
                         OnExtensionHandleEvent)
     IPC_MESSAGE_HANDLER(ViewMsg_Extension_SetFunctionNames,
                         OnSetExtensionFunctionNames)
+    IPC_MESSAGE_HANDLER(ViewMsg_PurgePluginListCache,
+                        OnPurgePluginListCache)
   IPC_END_MESSAGE_MAP()
 }
 
@@ -335,3 +339,13 @@ void RenderThread::OnExtensionHandleEvent(const std::string event_name,
                                           const std::string event_data) {
   RendererExtensionBindings::HandleEvent(event_name, event_data);
 }
+
+void RenderThread::OnPurgePluginListCache() {
+  // The call below will cause a GetPlugins call with refresh=true, but at this
+  // point we already know that the browser has refreshed its list, so disable
+  // refresh temporarily to prevent each renderer process causing the list to be
+  // regenerated.
+  plugin_refresh_allowed_ = false;
+  WebKit::resetPluginCache();
+  plugin_refresh_allowed_ = true;
+}

chrome/renderer/render_thread.h

@@ -91,6 +91,8 @@ class RenderThread : public RenderThreadBase,
     return user_script_slave_.get();
   }
 
+  bool plugin_refresh_allowed() const { return plugin_refresh_allowed_; }
+
   // Do DNS prefetch resolution of a hostname.
   void Resolve(const char* name, size_t length);
 
@@ -129,6 +131,7 @@ class RenderThread : public RenderThreadBase,
   void OnExtensionHandleMessage(const std::string& message, int channel_id);
   void OnExtensionHandleEvent(const std::string event_name,
       const std::string event_data);
+  void OnPurgePluginListCache();
 
   // Gather usage statistics from the in-memory cache and inform our host.
   // These functions should be call periodically so that the host can make
@@ -157,6 +160,9 @@ class RenderThread : public RenderThreadBase,
 
   scoped_refptr<DevToolsAgentFilter> devtools_agent_filter_;
 
+  // If true, then a GetPlugins call is allowed to rescan the disk.
+  bool plugin_refresh_allowed_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderThread);
 };
 

chrome/renderer/renderer_glue.cc

@@ -215,8 +215,10 @@ std::string GetUIResourceProtocol() {
 }
 
 bool GetPlugins(bool refresh, std::vector<WebPluginInfo>* plugins) {
-  return RenderThread::current()->Send(
-      new ViewHostMsg_GetPlugins(refresh, plugins));
+  if (!RenderThread::current()->plugin_refresh_allowed())
+    refresh = false;
+  return RenderThread::current()->Send(new ViewHostMsg_GetPlugins(
+     refresh, plugins));
 }
 
 // static factory function

webkit/glue/plugins/plugin_constants_win.h

@@ -33,4 +33,7 @@
 // plugin process to paint a window.
 #define kPaintMessageName L"Chrome_CustomPaint"
 
+// The name of the registry key which NPAPI plugins update on installation.
+#define kRegistryMozillaPlugins L"SOFTWARE\\MozillaPlugins"
+
 #endif  // WEBKIT_GLUE_PLUGIN_PLUGIN_LIST_H_

webkit/glue/plugins/plugin_list_win.cc

@@ -26,7 +26,6 @@ const TCHAR kRegistryAcrobatReader[] = _T("AcroRd32.exe");
 const TCHAR kRegistryWindowsMedia[] = _T("wmplayer.exe");
 const TCHAR kRegistryQuickTime[] = _T("QuickTimePlayer.exe");
 const TCHAR kRegistryPath[] = _T("Path");
-const TCHAR kRegistryMozillaPlugins[] = _T("SOFTWARE\\MozillaPlugins");
 const TCHAR kRegistryFirefoxInstalled[] =
     _T("SOFTWARE\\Mozilla\\Mozilla Firefox");
 const TCHAR kMozillaActiveXPlugin[] = _T("npmozax.dll");