Fix for crash when deleting DataSource's in IO thread.

chrome/browser/dom_ui/chrome_url_data_manager.cc

Index: chrome/browser/dom_ui/chrome_url_data_manager.cc
diff --git a/chrome/browser/dom_ui/chrome_url_data_manager.cc b/chrome/browser/dom_ui/chrome_url_data_manager.cc
index 5b69fe543baa61f3ec36e027ae7cb64736f56114..3193d7b2c64e1fbda3e16e2b1d2153e8d0fd8268 100644
--- a/chrome/browser/dom_ui/chrome_url_data_manager.cc
+++ b/chrome/browser/dom_ui/chrome_url_data_manager.cc
@@ -5,12 +5,14 @@
 #include "chrome/browser/dom_ui/chrome_url_data_manager.h"
 
 #include "app/l10n_util.h"
+  #include "base/debug/stack_trace.h"

[eroman, 2011/01/19 22:47:01]

Is this intentional? Please remove.

[ahendrickson, 2011/01/21 16:04:31]

Cleanup fail.

Removed.

 #include "base/file_util.h"
 #include "base/i18n/rtl.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/ref_counted_memory.h"
 #include "base/singleton.h"
+#include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "base/threading/thread.h"
 #include "base/values.h"
@@ -186,9 +188,29 @@ ChromeURLDataManager* ChromeURLDataManager::GetInstance() {
 void ChromeURLDataManager::AddDataSource(scoped_refptr<DataSource> source) {
   // TODO(jackson): A new data source with same name should not clobber the
   // existing one.
+  if (ContainsKey(data_sources_, source->source_name())) {
+    // Some |DataSource| derived classes contain |CancellationFlag| members,
+    // which DCHECK if they are deleted in a different thread than they are
+    // created in.  This is the IO thread, so we can't delete it here (for
+    // example, by reassigning a |data_sources_| entry).
+    // Create another reference and post a call to the UI thread to delete it.
+    // Any classes that weren't created on the UI thread are thread safe,
+    // and won't care if they're deleted on another thread.
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        NewRunnableMethod(
+            ChromeURLDataManager::GetInstance(),
+            &ChromeURLDataManager::ReleaseDataSource,
+            source));
+  }
   data_sources_[source->source_name()] = source;
 }
 
+void ChromeURLDataManager::ReleaseDataSource(scoped_refptr<DataSource> source) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  source.release();
+}
+
 void ChromeURLDataManager::AddFileSource(const std::string& source_name,
                                          const FilePath& file_path) {
   DCHECK(file_sources_.count(source_name) == 0);