Added functions on libjingle API to start and stop the recording of an RtcEventLog.

webrtc/call/rtc_event_log.cc

Index: webrtc/call/rtc_event_log.cc
diff --git a/webrtc/call/rtc_event_log.cc b/webrtc/call/rtc_event_log.cc
index 23b120cb8ed1fa4348b092561bb2d54cea6562f1..c00eb4b55ca29f420c02f052670aa133486080fd 100644
--- a/webrtc/call/rtc_event_log.cc
+++ b/webrtc/call/rtc_event_log.cc
@@ -11,6 +11,7 @@
 #include "webrtc/call/rtc_event_log.h"
 
 #include <deque>
+#include <limits>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/criticalsection.h"
@@ -37,6 +38,7 @@ namespace webrtc {
 class RtcEventLogImpl final : public RtcEventLog {
  public:
   void StartLogging(const std::string& file_name, int duration_ms) override {}
+  int StartLogging(FILE* log_file) override { return -1; }
   void StopLogging(void) override {}
   void LogVideoReceiveStreamConfig(
       const VideoReceiveStream::Config& config) override {}
@@ -60,6 +62,7 @@ class RtcEventLogImpl final : public RtcEventLog {
   RtcEventLogImpl();
 
   void StartLogging(const std::string& file_name, int duration_ms) override;
+  int StartLogging(FILE* log_file) override;
   void StopLogging() override;
   void LogVideoReceiveStreamConfig(
       const VideoReceiveStream::Config& config) override;
@@ -75,6 +78,9 @@ class RtcEventLogImpl final : public RtcEventLog {
   void LogAudioPlayout(uint32_t ssrc) override;
 
  private:
+  // Starts logging. This function assumes the file_ has been opened succesfully
+  // and that the start_time_us_ and _duration_us_ have been set.
+  void StartLoggingLocked() EXCLUSIVE_LOCKS_REQUIRED(crit_);
   // Stops logging and clears the stored data and buffers.
   void StopLoggingLocked() EXCLUSIVE_LOCKS_REQUIRED(crit_);
   // Adds a new event to the logfile if logging is active, or adds it to the
@@ -159,9 +165,29 @@ void RtcEventLogImpl::StartLogging(const std::string& file_name,
   if (file_->OpenFile(file_name.c_str(), false) != 0) {
     return;
   }
-  currently_logging_ = true;
   start_time_us_ = clock_->TimeInMicroseconds();
   duration_us_ = static_cast<int64_t>(duration_ms) * 1000;
+  StartLoggingLocked();
+}
+
+int RtcEventLogImpl::StartLogging(FILE* log_file) {
+  rtc::CritScope lock(&crit_);
+
+  if (currently_logging_)
+    StopLoggingLocked();
+  RTC_DCHECK(log_file);
+  if (file_->OpenFromFileHandle(log_file, true, false) != 0) {
+    return -1;
+  }
+  // Set the start time and duration to keep logging 'indefinitely'.
+  start_time_us_ = 0;
+  duration_us_ = std::numeric_limits<int64_t>::max();
+  StartLoggingLocked();
+  return 0;
+}
+
+void RtcEventLogImpl::StartLoggingLocked() {
+  currently_logging_ = true;
   // Write all the recent events to the log file, ignoring any old events.
   for (auto& event : recent_log_events_) {
     if (event.timestamp_us() >= start_time_us_ - recent_log_duration_us) {