Add UMA metric: Startup.BrowserMainToRendererMain.

content/renderer/renderer_main.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/debug/debugger.h"
 #include "base/debug/leak_annotations.h"
 #include "base/feature_list.h"
 #include "base/i18n/rtl.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/pending_task.h"
 #include "base/strings/string_util.h"
 #include "base/sys_info.h"
 #include "base/threading/platform_thread.h"
+#include "base/time/time.h"
 #include "base/timer/hi_res_timer_manager.h"
 #include "base/trace_event/trace_event.h"
 #include "components/scheduler/renderer/renderer_scheduler.h"
+#include "components/startup_metric_utils/common/startup_metric_messages.h"
 #include "content/child/child_process.h"
 #include "content/common/content_constants_internal.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/main_function_params.h"
 #include "content/public/renderer/content_renderer_client.h"
 #include "content/renderer/render_process_impl.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/renderer_main_platform_delegate.h"
 #include "third_party/skia/include/core/SkGraphics.h"
 #include "ui/base/ui_base_switches.h"
@@ skipping 43 matching lines @@
 #endif
 
 }  // namespace
 
 // mainline routine for running as the Renderer process
 int RendererMain(const MainFunctionParams& parameters) {
   // Don't use the TRACE_EVENT0 macro because the tracing infrastructure doesn't
   // expect synchronous events around the main loop of a thread.
   TRACE_EVENT_ASYNC_BEGIN0("startup", "RendererMain", 0);
 
+  base::Time renderer_main_entry_time = base::Time::Now();
+
   base::trace_event::TraceLog::GetInstance()->SetProcessName("Renderer");
   base::trace_event::TraceLog::GetInstance()->SetProcessSortIndex(
       kTraceEventRendererProcessSortIndex);
 
   const base::CommandLine& parsed_command_line = parameters.command_line;
 
 #if defined(OS_MACOSX)
   base::mac::ScopedNSAutoreleasePool* pool = parameters.autorelease_pool;
 #endif  // OS_MACOSX
 
@@ skipping 98 matching lines @@
                              renderer_scheduler.Pass());
 #endif
     bool run_loop = true;
     if (!no_sandbox)
       run_loop = platform.EnableSandbox();
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
     RenderProcessImpl render_process;
     RenderThreadImpl::Create(main_message_loop.Pass(),
                              renderer_scheduler.Pass());
 #endif
+    RenderThreadImpl::current()->Send(
+        new StartupMetricHostMsg_RecordRendererMainEntryTime(
+            renderer_main_entry_time.ToInternalValue()));

[gab, 2015/11/06 18:05:17]

I would think the IPC layer already knows how to serialize base::Time, have you
tried passing the base::Time object as-is?

[fdoray, 2015/11/09 15:53:56]

Done.

+
     base::HighResolutionTimerManager hi_res_timer_manager;
 
     if (run_loop) {
 #if defined(OS_MACOSX)
       if (pool)
         pool->Recycle();
 #endif
       TRACE_EVENT_ASYNC_BEGIN0("toplevel", "RendererMain.START_MSG_LOOP", 0);
       base::MessageLoop::current()->Run();
       TRACE_EVENT_ASYNC_END0("toplevel", "RendererMain.START_MSG_LOOP", 0);
     }
 #if defined(LEAK_SANITIZER)
     // Run leak detection before RenderProcessImpl goes out of scope. This helps
     // ignore shutdown-only leaks.
     __lsan_do_leak_check();
 #endif
   }
   platform.PlatformUninitialize();
   TRACE_EVENT_ASYNC_END0("startup", "RendererMain", 0);
   return 0;
 }
 
 }  // namespace content