Convert WebRtcLoggingHandlerHost to use the blocking thread pool.

chrome/browser/media/webrtc_log_uploader.cc

Index: chrome/browser/media/webrtc_log_uploader.cc
===================================================================
--- chrome/browser/media/webrtc_log_uploader.cc	(revision 274367)
+++ chrome/browser/media/webrtc_log_uploader.cc	(working copy)
@@ -76,7 +76,7 @@
     : log_count_(0),
       post_data_(NULL),
       shutting_down_(false) {
-  file_thread_checker_.DetachFromThread();
+  blocking_sequence_checker_.DetachFromSequence();
 }
 
 WebRtcLogUploader::~WebRtcLogUploader() {
@@ -102,8 +102,7 @@
       // TODO(jiayl): Add the RTP dump records to chrome://webrtc-logs.
       base::FilePath log_list_path =
           WebRtcLogList::GetWebRtcLogListFileForDirectory(it->second.log_path);
-      content::BrowserThread::PostTask(
-          content::BrowserThread::FILE,
+      content::BrowserThread::PostBlockingPoolTask(
           FROM_HERE,
           base::Bind(&WebRtcLogUploader::AddUploadedLogInfoToUploadListFile,
                      base::Unretained(this),
@@ -141,7 +140,7 @@
     uint32 length,
     const std::map<std::string, std::string>& meta_data,
     const WebRtcLogUploadDoneData& upload_done_data) {
-  DCHECK(file_thread_checker_.CalledOnValidThread());
+  DCHECK(blocking_sequence_checker_.CalledOnValidSequencedThread());
   DCHECK(log_buffer.get());
   DCHECK(!upload_done_data.log_path.empty());
 
@@ -352,7 +351,7 @@
 void WebRtcLogUploader::WriteCompressedLogToFile(
     const std::vector<uint8>& compressed_log,
     const base::FilePath& log_file_path) {
-  DCHECK(file_thread_checker_.CalledOnValidThread());
+  DCHECK(blocking_sequence_checker_.CalledOnValidSequencedThread());
   DCHECK(!compressed_log.empty());
   base::WriteFile(log_file_path,
                   reinterpret_cast<const char*>(&compressed_log[0]),
@@ -362,7 +361,7 @@
 void WebRtcLogUploader::AddLocallyStoredLogInfoToUploadListFile(
     const base::FilePath& upload_list_path,
     const std::string& local_log_id) {
-  DCHECK(file_thread_checker_.CalledOnValidThread());
+  DCHECK(blocking_sequence_checker_.CalledOnValidSequencedThread());
   DCHECK(!upload_list_path.empty());
   DCHECK(!local_log_id.empty());
 
@@ -406,7 +405,7 @@
     const base::FilePath& upload_list_path,
     const std::string& local_log_id,
     const std::string& report_id) {
-  DCHECK(file_thread_checker_.CalledOnValidThread());
+  DCHECK(blocking_sequence_checker_.CalledOnValidSequencedThread());
   DCHECK(!upload_list_path.empty());
   DCHECK(!local_log_id.empty());
   DCHECK(!report_id.empty());