Print some output in long perf tests, to keep them alive

webrtc/video/full_stack.cc

Index: webrtc/video/full_stack.cc
diff --git a/webrtc/video/full_stack.cc b/webrtc/video/full_stack.cc
index 008116cc7007bf08e47b1af934566a533bf09cbb..5284efd746d9fc8e11e23367fe508baa6d8eefc0 100644
--- a/webrtc/video/full_stack.cc
+++ b/webrtc/video/full_stack.cc
@@ -222,6 +222,7 @@ class VideoAnalyzer : public PacketReceiver,
 
     int last_frames_processed = -1;
     EventTypeWrapper eventType;
+    int iteration = 0;
     while ((eventType = done_->Wait(FullStackTest::kDefaultTimeoutMs)) !=
            kEventSignaled) {
       int frames_processed;
@@ -229,6 +230,14 @@ class VideoAnalyzer : public PacketReceiver,
         rtc::CritScope crit(&comparison_lock_);
         frames_processed = frames_processed_;
       }
+
+      // Print some output so test infrastructure won't think we've crashed.
+      const char* kKeepAliveMessages[3] = {
+          "Uh, I'm-I'm not quite dead, sir.",
+          "Uh, I-I think uh, I could pull through, sir.",
+          "Actually, I think I'm all right to come with you--"};
+      printf("- %s\n", kKeepAliveMessages[iteration++ % 3]);
+
       if (last_frames_processed == -1) {
         last_frames_processed = frames_processed;
         continue;
@@ -238,6 +247,9 @@ class VideoAnalyzer : public PacketReceiver,
       last_frames_processed = frames_processed;
     }
 
+    if (iteration > 0)
+      printf("- Farewell, sweet Concorde!\n");
+
     // Signal stats polling thread if that is still waiting and stop it now,
     // since it uses the send_stream_ reference that might be reclaimed after
     // returning from this method.