Don't attempt to unload Silverlight on the Mac

BUG=28131
TEST=covered by buildbot (no user-visible effect since the crash happens after the pages are closed)

Review URL: http://codereview.chromium.org/597027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38811 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 19 insertions, 3 deletions

diff --git a/webkit/glue/plugins/plugin_lib.cc b/webkit/glue/plugins/plugin_lib.cc
index 2768fc7..d63045a 100644
--- a/webkit/glue/plugins/plugin_lib.cc
+++ b/webkit/glue/plugins/plugin_lib.cc
@@ -64,7 +64,8 @@ PluginLib::PluginLib(const WebPluginInfo& info,
       library_(0),
       initialized_(false),
       saved_data_(0),
-      instance_count_(0) {
+      instance_count_(0),
+      skip_unload_(false) {
   StatsCounter(kPluginLibrariesLoadedCounter).Increment();
   memset((void*)&plugin_funcs_, 0, sizeof(plugin_funcs_));
   g_loaded_libs->push_back(this);
@@ -127,6 +128,10 @@ void PluginLib::NP_Shutdown(void) {
   entry_points_.np_shutdown();
 }
 
+void PluginLib::PreventLibraryUnload() {
+  skip_unload_ = true;
+}
+
 PluginInstance* PluginLib::CreateInstance(const std::string& mime_type) {
   PluginInstance* new_instance = new PluginInstance(this, mime_type);
   instance_count_++;
@@ -259,11 +264,13 @@ void PluginLib::Unload() {
 
     if (defer_unload) {
       FreePluginLibraryTask* free_library_task =
-          new FreePluginLibraryTask(library_, entry_points_.np_shutdown);
+          new FreePluginLibraryTask(skip_unload_ ? NULL : library_,
+                                    entry_points_.np_shutdown);
       MessageLoop::current()->PostTask(FROM_HERE, free_library_task);
     } else {
       Shutdown();
-      base::UnloadNativeLibrary(library_);
+      if (!skip_unload_)
+        base::UnloadNativeLibrary(library_);
     }
 
     library_ = 0;
diff --git a/webkit/glue/plugins/plugin_lib.h b/webkit/glue/plugins/plugin_lib.h
index 7dded2f..6af2893 100644
--- a/webkit/glue/plugins/plugin_lib.h
+++ b/webkit/glue/plugins/plugin_lib.h
@@ -74,6 +74,10 @@ class PluginLib : public base::RefCounted<PluginLib> {
 
   int instance_count() const { return instance_count_; }
 
+  // Prevents the library code from being unload when Unload() is called (since
+  // some plugins crash if unloaded).
+  void PreventLibraryUnload();
+
  private:
   friend class base::RefCounted<PluginLib>;
 
@@ -102,6 +106,7 @@ class PluginLib : public base::RefCounted<PluginLib> {
   bool initialized_;  // Is the plugin initialized?
   NPSavedData *saved_data_;  // Persisted plugin info for NPAPI.
   int instance_count_;  // Count of plugins in use.
+  bool skip_unload_;  // True if library_ should not be unloaded.
 
   // Function pointers to entry points into the plugin.
   PluginEntryPoints entry_points_;
diff --git a/webkit/glue/plugins/webplugin_delegate_impl_mac.mm b/webkit/glue/plugins/webplugin_delegate_impl_mac.mm
index 014e755..4b5c093 100644
--- a/webkit/glue/plugins/webplugin_delegate_impl_mac.mm
+++ b/webkit/glue/plugins/webplugin_delegate_impl_mac.mm
@@ -219,6 +219,10 @@ void WebPluginDelegateImpl::PlatformInitialize() {
   // destroyPlugin in WebNetscapePluginView.mm, for examples).
   quirks_ |= PLUGIN_QUIRK_DONT_SET_NULL_WINDOW_HANDLE_ON_DESTROY;
 
+  // Silverlight doesn't always unload cleanly, so don't unload it at shutdown.
+  if (instance()->mime_type().find("x-silverlight") != std::string::npos)
+    instance()->plugin_lib()->PreventLibraryUnload();
+
 #ifndef NP_NO_CARBON
   if (instance()->event_model() == NPEventModelCarbon) {
     // Create a stand-in for the browser window so that the plugin will have