Revert 123140 - Use SequencedWorkerPool for disk operations in TraceSubscriberStdio.

Reverted since it causes compile failure on Win/Aura. 
(scoped_refptr of TraceSubscriberStdioImpl which is only forward-declared)

This class was hitting a ThreadRestrictions assert because it called
OpenFile on the UI thread. To reduce unnecessary copying, I've changed
the OnTraceDataCollected argument from std::string to RefCountedString.

BUG=None
TEST=content_unittests

Review URL: http://codereview.chromium.org/9333003

TBR=husky@chromium.org
Review URL: https://chromiumcodereview.appspot.com/9447003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@123146 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 8 insertions, 5 deletions

diff --git a/base/debug/trace_event_impl.cc b/base/debug/trace_event_impl.cc
index fbe315e..1f23c36 100644
--- a/base/debug/trace_event_impl.cc
+++ b/base/debug/trace_event_impl.cc
@@ -564,7 +564,7 @@ void TraceLog::Flush() {
     TraceEvent::AppendEventsAsJSON(previous_logged_events,
                                    i,
                                    kTraceEventBatchSize,
-                                   &(json_events_str_ptr->data()));
+                                   &(json_events_str_ptr->data));
     output_callback_copy.Run(json_events_str_ptr);
   }
 }
diff --git a/base/debug/trace_event_impl.h b/base/debug/trace_event_impl.h
index 04aea18..1806f893 100644
--- a/base/debug/trace_event_impl.h
+++ b/base/debug/trace_event_impl.h
@@ -42,6 +42,8 @@ struct StaticMemorySingletonTraits;
 
 namespace base {
 
+class RefCountedString;
+
 namespace debug {
 
 const int kTraceMaxNumArgs = 2;
@@ -219,7 +221,8 @@ class BASE_EXPORT TraceLog {
   // silently dropped. The callback must be thread safe. The string format is
   // undefined. Use TraceResultBuffer to convert one or more trace strings to
   // JSON.
-  typedef base::Callback<void(const scoped_refptr<base::RefCountedString>&)>
+  typedef RefCountedData<std::string> RefCountedString;
+  typedef base::Callback<void(const scoped_refptr<RefCountedString>&)>
       OutputCallback;
   void SetOutputCallback(const OutputCallback& cb);
 
diff --git a/base/debug/trace_event_unittest.cc b/base/debug/trace_event_unittest.cc
index befd4e8..9afd68b 100644
--- a/base/debug/trace_event_unittest.cc
+++ b/base/debug/trace_event_unittest.cc
@@ -42,7 +42,7 @@ class TraceEventTestFixture : public testing::Test {
   // up multiple times when testing AtExit. Use ManualTestSetUp for this.
   void ManualTestSetUp();
   void OnTraceDataCollected(
-      const scoped_refptr<base::RefCountedString>& events_str);
+      const scoped_refptr<TraceLog::RefCountedString>& events_str);
   DictionaryValue* FindMatchingTraceEntry(const JsonKeyValue* key_values);
   DictionaryValue* FindNamePhase(const char* name, const char* phase);
   DictionaryValue* FindNamePhaseKeyValue(const char* name,
@@ -91,11 +91,11 @@ void TraceEventTestFixture::ManualTestSetUp() {
 }
 
 void TraceEventTestFixture::OnTraceDataCollected(
-    const scoped_refptr<base::RefCountedString>& events_str) {
+    const scoped_refptr<TraceLog::RefCountedString>& events_str) {
   AutoLock lock(lock_);
   json_output_.json_output.clear();
   trace_buffer_.Start();
-  trace_buffer_.AddFragment(events_str->data());
+  trace_buffer_.AddFragment(events_str->data);
   trace_buffer_.Finish();
 
   scoped_ptr<Value> root;