Allow audio debug recordings through a private API extension.

chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_api.cc

Index: chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_api.cc
diff --git a/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_api.cc b/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_api.cc
index cefad21fbc903acd54f389614e2064f38613be4d..fae1f0cf987423329c201fa364d32311ce21ed46 100644
--- a/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_api.cc
+++ b/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_api.cc
@@ -4,13 +4,16 @@
 
 #include "chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_api.h"
 
+#include "base/command_line.h"
 #include "base/hash.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/supports_user_data.h"
+#include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/common/chrome_switches.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/site_instance.h"
@@ -36,12 +39,63 @@ namespace StopRtpDump = api::webrtc_logging_private::StopRtpDump;
 namespace Store = api::webrtc_logging_private::Store;
 namespace Upload = api::webrtc_logging_private::Upload;
 namespace UploadStored = api::webrtc_logging_private::UploadStored;
+namespace StartAecDump = api::webrtc_logging_private::StartAecDump;
+namespace StopAecDump = api::webrtc_logging_private::StopAecDump;
 
 namespace {
 std::string HashIdWithOrigin(const std::string& security_origin,
                              const std::string& log_id) {
   return base::UintToString(base::Hash(security_origin + log_id));
 }
+
+uint64 current_aec_dump_id = 0;
+bool is_dump_in_progress = false;

[tommi (sloooow) - chröme, 2015/12/17 11:03:26]

document what thread these variables are used on.
also, for non-const ones add g_ prefix.  Actually, can those be member variables
of the AecDump function class?

[Guido Urdaneta, 2015/12/17 14:35:40]

Done.

+char kDumpFilePrefix[] = "aecdump.";

[tommi (sloooow) - chröme, 2015/12/17 11:03:26]

const

[Guido Urdaneta, 2015/12/17 14:35:40]

Done.

+
+// Starts AEC dump and save the files in the |dump_dir| directory, provided
+// no dump is in progress. Returns a UTF8 string with the prefix common to all
+// files produced by the dump (includes |dump_dir| and dump ID).
+// If there is a dump in progress, returns an empty string.
+std::string DoStartAecDump(const base::FilePath& dump_dir) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  if (is_dump_in_progress)
+    return std::string();
+
+  current_aec_dump_id++;

[tommi (sloooow) - chröme, 2015/12/17 11:03:26]

++foo;

[Guido Urdaneta, 2015/12/17 14:35:40]

Done.

+  base::FilePath prefix_path = dump_dir.Append(
+      kDumpFilePrefix + base::Int64ToString(current_aec_dump_id));
+  is_dump_in_progress = true;
+  for (content::RenderProcessHost::iterator i(
+           content::RenderProcessHost::AllHostsIterator());
+       !i.IsAtEnd(); i.Advance()) {
+    i.GetCurrentValue()->EnableAudioDebugRecordings(prefix_path);
+  }
+
+  return prefix_path.AsUTF8Unsafe();
+}
+
+// If |dump_id| is zero or the ID of the current AEC dump, stops the current
+// AEC dump. Otherwise, does nothing.
+void DoStopAecDump(uint64 dump_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // Prevent a old posted StopAecDump() call to stop a newer dump.

[tommi (sloooow) - chröme, 2015/12/17 11:03:26]

nit: Prevent an old posted StopAecDump() call from stopping a newer dump.

[Guido Urdaneta, 2015/12/17 14:35:40]

Done.

+  // This could happen in a sequence like:
+  //   Start(10);  //Start dump 1. Post Stop() to run after 10 seconds.
+  //   Stop();  // Manually stop dump 1 before 10 seconds;
+  //   Start(20);  // Start dump 2. Posted Stop() for 1 should not stop dump 2.
+  if (dump_id != 0 && dump_id < current_aec_dump_id)
+    return;
+
+  DCHECK_LE(dump_id, current_aec_dump_id);

[tommi (sloooow) - chröme, 2015/12/17 11:03:26]

I don't think this DCHECK will ever hit due to the previous if()

[Guido Urdaneta, 2015/12/17 14:35:42]

Moved to the beginning of the function.

+  for (content::RenderProcessHost::iterator i(
+           content::RenderProcessHost::AllHostsIterator());
+       !i.IsAtEnd(); i.Advance()) {
+    i.GetCurrentValue()->DisableAudioDebugRecordings();
+  }
+
+  is_dump_in_progress = false;
+}
 }  // namespace
 
 content::RenderProcessHost* WebrtcLoggingPrivateFunction::RphFromRequest(
@@ -124,6 +178,21 @@ void WebrtcLoggingPrivateFunctionWithUploadCallback::FireCallback(
   SendResponse(success);
 }
 
+void WebrtcLoggingPrivateFunctionWithAecDumpStartedCallback::FireCallback(
+    bool success,
+    const std::string& prefix_path,
+    const std::string& error_message) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  if (success) {
+    api::webrtc_logging_private::AecDumpInfo result;
+    result.prefix_path = prefix_path;
+    SetResult(result.ToValue().release());
+  } else {
+    SetError(error_message);
+  }
+  SendResponse(success);
+}
+
 bool WebrtcLoggingPrivateSetMetaDataFunction::RunAsync() {
   scoped_ptr<SetMetaData::Params> params(SetMetaData::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
@@ -348,4 +417,47 @@ bool WebrtcLoggingPrivateStopRtpDumpFunction::RunAsync() {
   return true;
 }
 
+bool WebrtcLoggingPrivateStartAecDumpFunction::RunAsync() {

[tommi (sloooow) - chröme, 2015/12/17 11:03:26]

do we need some sort of cleanup code here?  E.g. delete any old AEC recordings
to free up space?  Otherwise things are just going to build up.  We could e.g.
keep logs around for a week or so.

[Guido Urdaneta, 2015/12/17 14:35:40]

The functions are changed now so that the callback is always invoked after Stop
is invoked (either manually or automatically due to timeout).  At this point the
user can do the cleanup.

Implementing a cleanup policy ourselves would require changes to the lower
layers, no?

+  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableAecDumps)) {

[tommi (sloooow) - chröme, 2015/12/17 11:03:26]

can we call the constant kAllowAecDumpsFromExtension ?
Technically AEC dumps will be enabled via webrtc-internals, so I'd like to make
it clear for what functionality this switch is.

[Guido Urdaneta, 2015/12/17 14:35:42]

Done.

+    return false;
+  }
+
+  scoped_ptr<StartAecDump::Params> params(StartAecDump::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+  if (params->seconds < 0) {
+    FireCallback(false, std::string(),
+                 "seconds must be greater than or equal to 0");
+    return true;
+  }
+
+  DownloadPrefs download_prefs(GetProfile());
+  base::FilePath dump_dir = download_prefs.GetDefaultDownloadDirectory();
+  std::string prefix_path = DoStartAecDump(dump_dir);
+  if (prefix_path.empty())
+    FireCallback(false, std::string(), "AEC Dump already in progress");
+  else
+    FireCallback(true, prefix_path, std::string());
+
+  if (params->seconds > 0) {
+    BrowserThread::PostDelayedTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&DoStopAecDump, current_aec_dump_id),
+        base::TimeDelta::FromSeconds(params->seconds));
+  }
+
+  return true;
+}
+
+bool WebrtcLoggingPrivateStopAecDumpFunction::RunAsync() {
+  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableAecDumps)) {
+    return false;
+  }
+
+  DoStopAecDump(0);
+  FireCallback(true, std::string());
+  return true;
+}
+
 }  // namespace extensions