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 5f5f8e5cd2e4f24fc70aadafbd9586162a6a263e..1bf0c3e7289547219cde05ae588a64e5515c9e51 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"
@@ -757,6 +758,8 @@ 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)