Don't call NP_Shutdown in FreePluginLibraryTask if the library has already been reloaded.

webkit/glue/plugins/plugin_lib.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/glue/plugins/plugin_lib.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/metrics/stats_counters.h"
 #include "base/string_util.h"
@@ skipping 217 matching lines @@
       base::UnloadNativeLibrary(library);
     }
   }
 
   return rv;
 }
 
 // This class implements delayed NP_Shutdown and FreeLibrary on the plugin dll.
 class FreePluginLibraryTask : public Task {
  public:
-  FreePluginLibraryTask(base::NativeLibrary library,
+  FreePluginLibraryTask(const FilePath& path,
+                        base::NativeLibrary library,
                         NP_ShutdownFunc shutdown_func)
-      : library_(library),
+      : path_(path),
+        library_(library),
         NP_Shutdown_(shutdown_func) {
   }
 
   ~FreePluginLibraryTask() {}
 
   void Run() {
-    if (NP_Shutdown_)
-      NP_Shutdown_();
+    if (NP_Shutdown_) {
+      // Don't call NP_Shutdown if the library has been reloaded since this task
+      // was posted.
+      bool reloaded = false;
+      if (g_loaded_libs) {
+        for (size_t i = 0; i < g_loaded_libs->size(); ++i) {
+          if ((*g_loaded_libs)[i]->plugin_info().path == path_)
+            reloaded = true;
+        }
+      }
+      if (!reloaded)
+        NP_Shutdown_();
+    }
 
     if (library_) {
+      // Always call base::UnloadNativeLibrary so that the system reference
+      // count is decremented.
       base::UnloadNativeLibrary(library_);
       library_ = NULL;
     }
   }
 
  private:
+  FilePath path_;
   base::NativeLibrary library_;
   NP_ShutdownFunc NP_Shutdown_;
   DISALLOW_COPY_AND_ASSIGN(FreePluginLibraryTask);
 };
 
 void PluginLib::Unload() {
   if (!internal_ && library_) {
     // In case of single process mode, a plugin can delete itself
     // by executing a script. So delay the unloading of the library
     // so that the plugin will have a chance to unwind.
     bool defer_unload = webkit_glue::IsPluginRunningInRendererProcess();
 
 /* TODO(dglazkov): Revisit when re-enabling the JSC build.
 #if USE(JSC)
     // The plugin NPAPI instances may still be around. Delay the
     // NP_Shutdown and FreeLibrary calls at least till the next
     // peek message.
     defer_unload = true;
 #endif
 */
 
     if (defer_unload) {
       FreePluginLibraryTask* free_library_task =
-          new FreePluginLibraryTask(skip_unload_ ? NULL : library_,
+          new FreePluginLibraryTask(web_plugin_info_.path,
+                                    skip_unload_ ? NULL : library_,
                                     entry_points_.np_shutdown);
       LOG_IF(ERROR, PluginList::DebugPluginLoading())
           << "Scheduling delayed unload for plugin "
           << web_plugin_info_.path.value();
       MessageLoop::current()->PostTask(FROM_HERE, free_library_task);
     } else {
       Shutdown();
       if (!skip_unload_) {
         LOG_IF(ERROR, PluginList::DebugPluginLoading())
             << "Unloading plugin " << web_plugin_info_.path.value();
@@ skipping 17 matching lines @@
 }
 
 void PluginLib::Shutdown() {
   if (initialized_ && !internal_) {
     NP_Shutdown();
     initialized_ = false;
   }
 }
 
 }  // namespace NPAPI