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 188 matching lines @@
 #if defined(ENABLE_WEBRTC)
 // 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;
   base::PlatformFile aec_dump_file = base::CreatePlatformFile(
       file_path,
-      base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_WRITE,
+      base::PLATFORM_FILE_OPEN_ALWAYS | base::PLATFORM_FILE_APPEND,
       NULL,
       &error);
   if (error != base::PLATFORM_FILE_OK) {
     VLOG(1) << "Could not open AEC dump file, error=" << error;
     return IPC::InvalidPlatformFileForTransit();
   }
   return IPC::GetFileHandleForProcess(aec_dump_file, process, true);
 }
 
 // Does nothing. Just to avoid races between enable and disable.
 void DisableAecDumpOnFileThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 }
-
 #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 1841 matching lines @@
     return;
   Send(new MediaStreamMsg_EnableAecDump(file_for_transit));
 }
 
 void RenderProcessHostImpl::SendDisableAecDumpToRenderer() {
   Send(new MediaStreamMsg_DisableAecDump());
 }
 #endif
 
 }  // namespace content