Flapper field trial to use workerpool for sync file operations.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 9291e9f115c90b8a1a3f70aa66eab23b76a33dd8..134624ea56a499f5ee181d4e8808e3a6ad963f99 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -7,6 +7,7 @@
 #include <utility>
 
 #include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/stats_counters.h"
 #include "base/string16.h"
@@ -2328,6 +2329,20 @@ void WebContentsImpl::OnSetSelectedColorInColorChooser(int color_chooser_id,
 void WebContentsImpl::OnPepperPluginHung(int plugin_child_id,
                                          const FilePath& path,
                                          bool is_hung) {
+  HISTOGRAM_COUNTS("Pepper.PluginHung", 1);
+
+  // TODO(shess): http://crbug.com/153383 debugging.  Determine how
+  // often hangs happen when using worker pool versus FILE thread.
+  // kFieldTrialName needs to match the value in pepper_flash.cc, but
+  // plumbing that through would be disruptive for temporary code.
+  const char* const kFieldTrialName = "FlapperIOThread";

[yzshen1, 2012/10/02 23:33:44]

static, please.

[Scott Hess - ex-Googler, 2012/10/02 23:42:31]

OK.  But I think it's already implicitly static, since it's a constant pointer
to constant data.

+  static const bool hung_trial_exists =
+      base::FieldTrialList::TrialExists(kFieldTrialName);
+  if (hung_trial_exists) {
+    HISTOGRAM_COUNTS(base::FieldTrial::MakeName("Pepper.PluginHung",
+                                                kFieldTrialName), 1);
+  }
+
   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
                     PluginHungStatusChanged(plugin_child_id, path, is_hung));
 }