Print stack traces in child processes when browser tests failed.

content/app/content_main_runner.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 "content/public/app/content_main_runner.h"
 
 #include <stdlib.h>
 
 #include "base/allocator/allocator_extension.h"
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/debug/debugger.h"
+#include "base/debug/stack_trace.h"
 #include "base/files/file_path.h"
 #include "base/i18n/icu_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/path_service.h"
 #include "base/process/launch.h"
 #include "base/process/memory.h"
@@ skipping 165 matching lines @@
   // Various things break when you're using a locale where the decimal
   // separator isn't a period.  See e.g. bugs 22782 and 39964.  For
   // all processes except the browser process (where we call system
   // APIs that may rely on the correct locale for formatting numbers
   // when presenting them to the user), reset the locale for numeric
   // formatting.
   // Note that this is not correct for plugin processes -- they can
   // surface UI -- but it's likely they get this wrong too so why not.
   setlocale(LC_NUMERIC, "C");
 #endif
+
+#if !defined(OFFICIAL_BUILD)
+  // Print stack traces to stderr when crashes occur. This opens up security
+  // holes so it should never be enabled for official builds.
+  base::debug::EnableInProcessStackDumping();
+#if defined(OS_WIN)
+  base::RouteStdioToConsole(false);
+  LoadLibraryA("dbghelp.dll");

[brucedawson, 2016/04/18 23:07:00]

What is the purpose of this LoadLibrary call? The EnableInProcessStackDumping
function calls SymInitialize which loads dbghelp.dll - is this unintentionally
out-of-order or is supposed to increase the reference count?

+#endif
+#endif
 }
 
 class ContentClientInitializer {
  public:
   static void Set(const std::string& process_type,
                   ContentMainDelegate* delegate) {
     ContentClient* content_client = GetContentClient();
 #if !defined(CHROME_MULTIPLE_DLL_CHILD)
     if (process_type.empty()) {
       if (delegate)
@@ skipping 388 matching lines @@
       gfx::InitDeviceScaleFactor(gfx::GetDPIScale());
 #endif
 
     if (!GetContentClient())
       SetContentClient(&empty_content_client_);
     ContentClientInitializer::Set(process_type, delegate_);
 
 #if defined(OS_WIN)
     // Route stdio to parent console (if any) or create one.
     if (command_line.HasSwitch(switches::kEnableLogging))
-      base::RouteStdioToConsole();
+      base::RouteStdioToConsole(true);
 #endif
 
     // Enable startup tracing asap to avoid early TRACE_EVENT calls being
     // ignored.
     if (command_line.HasSwitch(switches::kTraceStartup)) {
       base::trace_event::TraceConfig trace_config(
           command_line.GetSwitchValueASCII(switches::kTraceStartup),
           base::trace_event::RECORD_UNTIL_FULL);
       base::trace_event::TraceLog::GetInstance()->SetEnabled(
           trace_config,
@@ skipping 234 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(ContentMainRunnerImpl);
 };
 
 // static
 ContentMainRunner* ContentMainRunner::Create() {
   return new ContentMainRunnerImpl();
 }
 
 }  // namespace content