Log a non-crash dump for 10% of Spitzer pipeline decode failures.

Spitzer is currently enabled as a 40% experiment on dev (soon on
beta as well), but we have abnormally high video-only decode
failure rates, so add some logging to try and track this down.

~10% of the time, this change will log the 'subresource_url' crash
key as a non-crash dump when a decode error is encountered on
Android where Spitzer is enabled.

This will allow us to investigate and triage these crashes. We're
already logging this key for normal crash dumps during DoLoad().

This is a temporary change which will be removed shortly after
landing once any issues are identified.

BUG=595076
TEST=none

Review URL: https://codereview.chromium.org/1808473002

Cr-Commit-Position: refs/heads/master@{#381532}

media/blink/webmediaplayer_impl.cc

@@ -17,7 +17,9 @@
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/debug/crash_logging.h"
+#include "base/debug/dump_without_crashing.h"
 #include "base/metrics/histogram.h"
+#include "base/rand_util.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/task_runner_util.h"
@@ -927,6 +929,16 @@ void WebMediaPlayerImpl::OnPipelineError(PipelineStatus error) {
   if (suppress_destruction_errors_)
     return;
 
+#if defined(OS_ANDROID)
+  // For 10% of pipeline decode failures log the playback URL. The URL is set
+  // as the crash-key 'subresource_url' during DoLoad().
+  //
+  // TODO(dalecurtis): This is temporary to track down higher than average
+  // decode failure rates for video-only content. See http://crbug.com/595076.
+  if (base::RandDouble() <= 0.1 && error == PIPELINE_ERROR_DECODE)
+    base::debug::DumpWithoutCrashing();
+#endif
+
   media_log_->AddEvent(media_log_->CreatePipelineErrorEvent(error));
 
   if (ready_state_ == WebMediaPlayer::ReadyStateHaveNothing) {