Prevent overflow when negative delay values are encountered.

Similar to 90a508cd, these values may
occur in the wild and should be avoided.

R=tguilbert

Change-Id: Id30a7175649c399ddb3f6c78e29c9beac55c00ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1913600
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Thomas Guilbert <tguilbert@chromium.org>
Auto-Submit: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Thomas Guilbert <tguilbert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714762}

media/base/audio_renderer_mixer.cc

@@ -11,6 +11,7 @@
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "media/base/audio_renderer_mixer_input.h"
 #include "media/base/audio_timestamp_helper.h"
@@ -169,6 +170,11 @@ int AudioRendererMixer::Render(base::TimeDelta delay,
     playing_ = false;
   }
 
+  // Since AudioConverter uses uint32_t for delay calculations, we must drop
+  // negative delay values (which are incorrect anyways).
+  if (delay < base::TimeDelta())
+    delay = base::TimeDelta();
+
   uint32_t frames_delayed =
       AudioTimestampHelper::TimeToFrames(delay, output_params_.sample_rate());
   master_converter_.ConvertWithDelay(frames_delayed, audio_bus);