Add stats collection for telemetry startup.warm.blank_page test.

mojo/runner/context.cc

Index: mojo/runner/context.cc
diff --git a/mojo/runner/context.cc b/mojo/runner/context.cc
index 39d0536973c48d12b19486658aa6ba6f5844bf9e..ef3bf2dfd256dd3a483517d939c548fa57a1ba33 100644
--- a/mojo/runner/context.cc
+++ b/mojo/runner/context.cc
@@ -14,6 +14,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/path_service.h"
+#include "base/process/process_info.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
@@ -313,6 +314,15 @@ bool Context::Init() {
       tracing_service_provider_ptr.Pass(),
       shell::GetPermissiveCapabilityFilter(), base::Closure());
 
+  // Record the shell process creation time for performance testing.
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kStatsCollectionController)) {
+    tracing::StartupPerformanceControllerPtr controller;
+    application_manager_.ConnectToService(GURL("mojo:tracing"), &controller);

[yzshen1, 2015/08/13 15:59:12]

Please consider directly obtaining a service provider from line 313, and ask for
a StartupPerformanceControllerPtr from it. That way we avoid the cost of
connecting to the application a second time.

[msw, 2015/08/14 23:20:35]

Done.

+    const base::Time creation_time = base::CurrentProcessInfo::CreationTime();
+    controller->SetShellProcessCreationTime(creation_time.ToInternalValue());
+  }
+
   InitDevToolsServiceIfNeeded(&application_manager_, command_line);
 
   return true;