Use ChromeThread::DeleteOnIOThread in a few places where an object must be deleted on a certain thread.

BUG=25354
Review URL: http://codereview.chromium.org/342090

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@30882 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 36 insertions, 63 deletions

diff --git a/chrome/browser/renderer_host/audio_renderer_host.cc b/chrome/browser/renderer_host/audio_renderer_host.cc
index 0fb3fe8..7ea64e7 100644
--- a/chrome/browser/renderer_host/audio_renderer_host.cc
+++ b/chrome/browser/renderer_host/audio_renderer_host.cc
@@ -25,7 +25,6 @@
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "base/waitable_event.h"
-#include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/renderer_host/audio_renderer_host.h"
 #include "chrome/common/render_messages.h"
 #include "ipc/ipc_logging.h"
@@ -335,14 +334,13 @@ AudioRendererHost::AudioRendererHost()
     : process_id_(0),
       process_handle_(0),
       ipc_sender_(NULL) {
-  // Make sure we perform actual initialization operations in the thread where
-  // this object should live.
-  ChromeThread::PostTask(
-      ChromeThread::IO, FROM_HERE,
-      NewRunnableMethod(this, &AudioRendererHost::OnInitialized));
+  // Increase the ref count of this object so it is active until we do
+  // Release().
+  AddRef();
 }
 
 AudioRendererHost::~AudioRendererHost() {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
   DCHECK(sources_.empty());
 }
 
@@ -498,13 +496,6 @@ void AudioRendererHost::OnNotifyPacketReady(const IPC::Message& msg,
   }
 }
 
-void AudioRendererHost::OnInitialized() {
-  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
-  // Increase the ref count of this object so it is active until we do
-  // Release().
-  AddRef();
-}
-
 void AudioRendererHost::OnDestroyed() {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
   ipc_sender_ = NULL;
diff --git a/chrome/browser/renderer_host/audio_renderer_host.h b/chrome/browser/renderer_host/audio_renderer_host.h
index 1a3b6e5..a1549dd 100644
--- a/chrome/browser/renderer_host/audio_renderer_host.h
+++ b/chrome/browser/renderer_host/audio_renderer_host.h
@@ -74,6 +74,7 @@
 #include "base/ref_counted.h"
 #include "base/shared_memory.h"
 #include "base/waitable_event.h"
+#include "chrome/browser/chrome_thread.h"
 #include "ipc/ipc_message.h"
 #include "media/audio/audio_output.h"
 #include "media/audio/simple_sources.h"
@@ -82,15 +83,16 @@
 class AudioManager;
 struct ViewHostMsg_Audio_CreateStream;
 
-class AudioRendererHost : public base::RefCountedThreadSafe<AudioRendererHost> {
+class AudioRendererHost
+    : public base::RefCountedThreadSafe<
+          AudioRendererHost, ChromeThread::DeleteOnIOThread> {
  private:
   class IPCAudioSource;
  public:
   // Called from UI thread from the owner of this object.
   AudioRendererHost();
 
-  // Destruction can happen on either UI thread or IO thread, but at destruction
-  // all associated sources are destroyed and streams are closed.
+  // Destruction always happens on the IO thread (see DeleteOnIOThread above).
   virtual ~AudioRendererHost();
 
   // Called from UI thread from the owner of this object to kick start
@@ -315,9 +317,6 @@ class AudioRendererHost : public base::RefCountedThreadSafe<AudioRendererHost> {
   void OnNotifyPacketReady(const IPC::Message& msg, int stream_id,
                            size_t packet_size);
 
-  // Called on IO thread when this object is created and initialized.
-  void OnInitialized();
-
   // Called on IO thread when this object needs to be destroyed and after
   // Destroy() is called from owner of this class in UI thread.
   void OnDestroyed();
diff --git a/chrome/browser/renderer_host/buffered_resource_handler.cc b/chrome/browser/renderer_host/buffered_resource_handler.cc
index 33e6489..6022e1f 100644
--- a/chrome/browser/renderer_host/buffered_resource_handler.cc
+++ b/chrome/browser/renderer_host/buffered_resource_handler.cc
@@ -9,7 +9,6 @@
 #include "base/histogram.h"
 #include "base/logging.h"
 #include "base/string_util.h"
-#include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/renderer_host/download_throttling_resource_handler.h"
 #include "chrome/browser/renderer_host/resource_dispatcher_host.h"
@@ -396,15 +395,9 @@ bool BufferedResourceHandler::ShouldWaitForPlugins() {
   host_->PauseRequest(info->child_id(), info->request_id(), true);
 
   // Schedule plugin loading on the file thread.
-  // Note: it's possible that the only reference to this object is the task.  If
-  // If the task executes on the file thread, and before it returns, the task it
-  // posts to the IO thread runs, then this object will get destructed on the
-  // file thread.  This breaks assumptions in other message handlers (i.e. when
-  // unregistering with NotificationService in the destructor).
-  AddRef();
   ChromeThread::PostTask(
       ChromeThread::FILE, FROM_HERE,
-      NewRunnableFunction(&BufferedResourceHandler::LoadPlugins, this));
+      NewRunnableMethod(this, &BufferedResourceHandler::LoadPlugins));
   return true;
 }
 
@@ -468,26 +461,23 @@ bool BufferedResourceHandler::ShouldDownload(bool* need_plugin_list) {
       GURL(), type, allow_wildcard, &info, NULL);
 }
 
-void BufferedResourceHandler::LoadPlugins(BufferedResourceHandler* handler) {
+void BufferedResourceHandler::LoadPlugins() {
   std::vector<WebPluginInfo> plugins;
   NPAPI::PluginList::Singleton()->GetPlugins(false, &plugins);
 
   ChromeThread::PostTask(
       ChromeThread::IO, FROM_HERE,
-      NewRunnableFunction(&BufferedResourceHandler::OnPluginsLoaded,
-          handler));
+      NewRunnableMethod(this, &BufferedResourceHandler::OnPluginsLoaded));
 }
 
-void BufferedResourceHandler::OnPluginsLoaded(
-    BufferedResourceHandler* handler) {
-  handler->wait_for_plugins_ = false;
-  if (handler->request_) {
-    ResourceDispatcherHostRequestInfo* info =
-        ResourceDispatcherHost::InfoForRequest(handler->request_);
-    handler->host_->PauseRequest(info->child_id(), info->request_id(), false);
-    if (!handler->CompleteResponseStarted(info->request_id(), false))
-      handler->host_->CancelRequest(
-          info->child_id(), info->request_id(), false);
-  }
-  handler->Release();
+void BufferedResourceHandler::OnPluginsLoaded() {
+  wait_for_plugins_ = false;
+  if (!request_)
+    return;
+
+  ResourceDispatcherHostRequestInfo* info =
+      ResourceDispatcherHost::InfoForRequest(request_);
+  host_->PauseRequest(info->child_id(), info->request_id(), false);
+  if (!CompleteResponseStarted(info->request_id(), false))
+    host_->CancelRequest(info->child_id(), info->request_id(), false);
 }
diff --git a/chrome/browser/renderer_host/buffered_resource_handler.h b/chrome/browser/renderer_host/buffered_resource_handler.h
index fa0e249..52608cc 100644
--- a/chrome/browser/renderer_host/buffered_resource_handler.h
+++ b/chrome/browser/renderer_host/buffered_resource_handler.h
@@ -62,10 +62,10 @@ class BufferedResourceHandler : public ResourceHandler {
   bool ShouldDownload(bool* need_plugin_list);
 
   // Called on the file thread to load the list of plugins.
-  static void LoadPlugins(BufferedResourceHandler* handler);
+  void LoadPlugins();
 
   // Called on the IO thread once the list of plugins has been loaded.
-  static void OnPluginsLoaded(BufferedResourceHandler* handler);
+  void OnPluginsLoaded();
 
   scoped_refptr<ResourceHandler> real_handler_;
   scoped_refptr<ResourceResponse> response_;
diff --git a/chrome/browser/renderer_host/resource_handler.h b/chrome/browser/renderer_host/resource_handler.h
index 39a85fa..f4fe726 100644
--- a/chrome/browser/renderer_host/resource_handler.h
+++ b/chrome/browser/renderer_host/resource_handler.h
@@ -14,6 +14,7 @@
 
 #include <string>
 
+#include "chrome/browser/chrome_thread.h"
 #include "chrome/common/filter_policy.h"
 #include "net/url_request/url_request_status.h"
 #include "webkit/glue/resource_loader_bridge.h"
@@ -52,7 +53,9 @@ struct ResourceResponse : public base::RefCounted<ResourceResponse> {
 // The resource dispatcher host uses this interface to push load events to the
 // renderer, allowing for differences in the types of IPC messages generated.
 // See the implementations of this interface defined below.
-class ResourceHandler : public base::RefCountedThreadSafe<ResourceHandler> {
+class ResourceHandler
+    : public base::RefCountedThreadSafe<
+          ResourceHandler, ChromeThread::DeleteOnIOThread> {
  public:
   virtual ~ResourceHandler() {}
 
diff --git a/chrome/browser/spellchecker.cc b/chrome/browser/spellchecker.cc
index 11142d0..856deac 100644
--- a/chrome/browser/spellchecker.cc
+++ b/chrome/browser/spellchecker.cc
@@ -13,7 +13,6 @@
 #include "base/path_service.h"
 #include "base/stats_counters.h"
 #include "base/string_util.h"
-#include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/net/url_fetcher.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/spellchecker_common.h"
@@ -221,15 +220,12 @@ class ReadDictionaryTask : public Task {
     ChromeThread::PostTask(
         ChromeThread::IO, FROM_HERE,
         NewRunnableMethod(
-            spellchecker_, &SpellChecker::HunspellInited, hunspell_,
+            spellchecker_.get(), &SpellChecker::HunspellInited, hunspell_,
             bdict_file_, file_existed));
   }
 
-  // The SpellChecker we are working for. We are guaranteed to be outlived
-  // by this object because it AddRefs() itself before calling us.
-  // Accessing it is not necessarily thread safe, but are careful to only access
-  // it in ways that are.
-  SpellChecker* spellchecker_;
+  // The SpellChecker we are working for.
+  scoped_refptr<SpellChecker> spellchecker_;
   Hunspell* hunspell_;
   file_util::MemoryMappedFile* bdict_file_;
 
@@ -537,8 +533,6 @@ bool SpellChecker::Initialize() {
   FilePath dictionary_file_name_usr = GetVersionedFileName(language_,
       dict_dir_userdata);
 
-  // Balances Release() in HunspellInited().
-  AddRef();
   ChromeThread::PostTask(
       ChromeThread::FILE, FROM_HERE,
       new ReadDictionaryTask(
@@ -560,9 +554,6 @@ void SpellChecker::HunspellInited(Hunspell* hunspell,
       // File didn't exist. We need to download a dictionary.
       DoDictionaryDownload();
     }
-
-    // Balances AddRef() in Initialize().
-    Release();
     return;
   }
 
@@ -574,9 +565,6 @@ void SpellChecker::HunspellInited(Hunspell* hunspell,
     hunspell_->add(custom_words_.front().c_str());
     custom_words_.pop();
   }
-
-  // Balances AddRef() in Initialize().
-  Release();
 }
 
 void SpellChecker::DoDictionaryDownload() {
diff --git a/chrome/browser/spellchecker.h b/chrome/browser/spellchecker.h
index 26315d8..303956c 100644
--- a/chrome/browser/spellchecker.h
+++ b/chrome/browser/spellchecker.h
@@ -13,7 +13,7 @@
 #include "base/string16.h"
 #include "base/task.h"
 #include "base/time.h"
-#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/net/url_fetcher.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/spellcheck_worditerator.h"
@@ -42,8 +42,10 @@ class MemoryMappedFile;
 // This object should also be deleted on the I/O thread only. It owns a
 // reference to URLRequestContext which in turn owns the cache, etc. and must be
 // deleted on the I/O thread itself.
-class SpellChecker : public base::RefCountedThreadSafe<SpellChecker>,
-                     public URLFetcher::Delegate {
+class SpellChecker
+    : public base::RefCountedThreadSafe<
+          SpellChecker, ChromeThread::DeleteOnIOThread>,
+      public URLFetcher::Delegate {
  public:
   // Creates the spellchecker by reading dictionaries from the given directory,
   // and defaulting to the given language. Both strings must be provided.