Report histogram creation results.

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index ba10cbb430c1d557b2521473079b6ead49cb6fd1..5c95ff64920ba999879e3a37a479fba2a30f0f07 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -23,6 +23,7 @@
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
+#include "base/metrics/histogram_base.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/path_service.h"
 #include "base/process/launch.h"
@@ -30,6 +31,7 @@
 #include "base/process/process_handle.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
@@ -752,6 +754,8 @@ class ContentMainRunnerImpl : public ContentMainRunner {
     std::string process_type =
         command_line.GetSwitchValueASCII(switches::kProcessType);
 
+    base::HistogramBase::EnableActivityReportHistogram(process_type);
+
     MainFunctionParams main_params(command_line);
     main_params.ui_task = ui_task_;
 #if defined(OS_WIN)