Don't overwrite WebRTC AEC dump file.

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright (c) 2012 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 179 matching lines @@
     const ResourceHostMsg_Request& request,
     ResourceContext** resource_context_out,
     net::URLRequestContext** request_context_out) {
   *resource_context_out = resource_context;
   *request_context_out =
       GetRequestContext(request_context, media_request_context,
                         request.resource_type);
 }
 
 #if defined(ENABLE_WEBRTC)
+// |first_aec_dump_open| is used for only opening the file so that it overwrites
+// an existing file the first time. Consecutive opens will append.

[sky, 2014/02/11 15:07:23]

'file the first create' ?

[Henrik Grunell, 2014/02/11 16:26:55]

Done.

+// TODO(grunell): How this flag is used together with the two functions is
+// confusing. We actually assume that CreateAecDumpFileForProcess will be called
+// with the same |file_path| for all processes. Refactoring needed.
+static bool first_aec_dump_open = true;

[sky, 2014/02/11 15:07:23]

How about naming this a bit more clearly. Say create_new_dump_file or the
inverse, append_to_existing_dump_file?

[Henrik Grunell, 2014/02/11 16:26:55]

Done.

+
 // Creates a file used for diagnostic echo canceller recordings for handing
 // over to the renderer.
 IPC::PlatformFileForTransit CreateAecDumpFileForProcess(
     base::FilePath file_path,
     base::ProcessHandle process) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   base::PlatformFileError error = base::PLATFORM_FILE_OK;
+  int flags = first_aec_dump_open ?
+      base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_WRITE :
+      base::PLATFORM_FILE_OPEN_ALWAYS | base::PLATFORM_FILE_APPEND;
   base::PlatformFile aec_dump_file = base::CreatePlatformFile(
       file_path,
-      base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_WRITE,
+      flags,
       NULL,
       &error);
   if (error != base::PLATFORM_FILE_OK) {
     VLOG(1) << "Could not open AEC dump file, error=" << error;
     return IPC::InvalidPlatformFileForTransit();
   }
+  first_aec_dump_open = false;
   return IPC::GetFileHandleForProcess(aec_dump_file, process, true);
 }
 
-// Does nothing. Just to avoid races between enable and disable.
+// We assume that this function is called for all render process hosts when
+// called. The first one called will reset the state so that when enabled
+// again, the file will be opened so that it overwrite an existing file.
 void DisableAecDumpOnFileThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  first_aec_dump_open = true;
 }
-
 #endif
 
 // the global list of all renderer processes
 base::LazyInstance<IDMap<RenderProcessHost> >::Leaky
     g_all_hosts = LAZY_INSTANCE_INITIALIZER;
 
 base::LazyInstance<scoped_refptr<BrowserPluginGeolocationPermissionContext> >
     g_browser_plugin_geolocation_context = LAZY_INSTANCE_INITIALIZER;
 
 // Map of site to process, to ensure we only have one RenderProcessHost per
@@ skipping 1290 matching lines @@
 #if defined(ENABLE_WEBRTC)
 void RenderProcessHostImpl::EnableAecDump(const base::FilePath& file) {
   BrowserThread::PostTaskAndReplyWithResult(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&CreateAecDumpFileForProcess, file, GetHandle()),
       base::Bind(&RenderProcessHostImpl::SendAecDumpFileToRenderer,
                  weak_factory_.GetWeakPtr()));
 }
 
 void RenderProcessHostImpl::DisableAecDump() {
-  // Posting on the FILE thread and then replying back on the UI thread is only
-  // for avoiding races between enable and disable. Nothing is done on the FILE
-  // thread.
   BrowserThread::PostTaskAndReply(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&DisableAecDumpOnFileThread),
       base::Bind(&RenderProcessHostImpl::SendDisableAecDumpToRenderer,
                  weak_factory_.GetWeakPtr()));
 }
 
 void RenderProcessHostImpl::SetWebRtcLogMessageCallback(
     base::Callback<void(const std::string&)> callback) {
   webrtc_log_message_callback_ = callback;
@@ skipping 526 matching lines @@
     return;
   Send(new MediaStreamMsg_EnableAecDump(file_for_transit));
 }
 
 void RenderProcessHostImpl::SendDisableAecDumpToRenderer() {
   Send(new MediaStreamMsg_DisableAecDump());
 }
 #endif
 
 }  // namespace content