headless: Add command line flags for logging

headless/lib/headless_content_main_delegate.cc

 // Copyright 2015 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 "headless/lib/headless_content_main_delegate.h"
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/run_loop.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/trace_event/trace_event.h"
 #include "content/public/browser/browser_main_runner.h"
 #include "content/public/common/content_switches.h"
 #include "headless/lib/browser/headless_browser_impl.h"
 #include "headless/lib/browser/headless_content_browser_client.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_switches.h"
 #include "ui/gfx/switches.h"
 #include "ui/gl/gl_switches.h"
 #include "ui/ozone/public/ozone_switches.h"
@@ skipping 42 matching lines @@
     command_line->AppendSwitchASCII(switches::kUseGL,
                                     browser_->options()->gl_implementation);
   } else {
     command_line->AppendSwitch(switches::kDisableGpu);
   }
 
   SetContentClient(&content_client_);
   return false;
 }
 
+void HeadlessContentMainDelegate::InitLogging(
+    const base::CommandLine& command_line) {
+  if (!command_line.HasSwitch(switches::kEnableLogging))
+    return;
+
+  logging::LoggingDestination log_mode;
+  base::FilePath log_filename(FILE_PATH_LITERAL("chrome_debug.log"));
+  if (command_line.GetSwitchValueASCII(switches::kEnableLogging) == "stderr") {
+    log_mode = logging::LOG_TO_SYSTEM_DEBUG_LOG;
+  } else {
+    base::FilePath custom_filename(
+        command_line.GetSwitchValuePath(switches::kEnableLogging));
+    if (custom_filename.empty()) {
+      log_mode = logging::LOG_TO_ALL;
+    } else {
+      log_mode = logging::LOG_TO_FILE;
+      log_filename = custom_filename;
+    }
+  }
+
+  if (command_line.HasSwitch(switches::kLoggingLevel) &&
+      logging::GetMinLogLevel() >= 0) {
+    std::string log_level =
+        command_line.GetSwitchValueASCII(switches::kLoggingLevel);
+    int level = 0;
+    if (base::StringToInt(log_level, &level) && level >= 0 &&
+        level < logging::LOG_NUM_SEVERITIES) {
+      logging::SetMinLogLevel(level);
+    } else {
+      DLOG(WARNING) << "Bad log level: " << log_level;
+    }
+  }
+
+  base::FilePath log_path;
+  logging::LoggingSettings settings;
+
+  if (PathService::Get(base::DIR_MODULE, &log_path)) {
+    log_path = log_path.Append(log_filename);
+  } else {
+    log_path = log_filename;
+  }
+
+  settings.logging_dest = log_mode;
+  settings.log_file = log_path.value().c_str();
+  settings.lock_log = logging::DONT_LOCK_LOG_FILE;
+  settings.delete_old = logging::DELETE_OLD_LOG_FILE;

[Eric Seckler, 2017/02/02 23:57:19]

I think, in renderer processes, this shouldn't be DELETE, but append.

+  bool success = logging::InitLogging(settings);
+  DCHECK(success);
+}
+
 void HeadlessContentMainDelegate::PreSandboxStartup() {
+  InitLogging(*base::CommandLine::ForCurrentProcess());
   InitializeResourceBundle();
 }
 
 int HeadlessContentMainDelegate::RunProcess(
     const std::string& process_type,
     const content::MainFunctionParams& main_function_params) {
   if (!process_type.empty())
     return -1;
 
   base::trace_event::TraceLog::GetInstance()->SetProcessName("HeadlessBrowser");
@@ skipping 47 matching lines @@
       pak_file, ui::SCALE_FACTOR_NONE);
 }
 
 content::ContentBrowserClient*
 HeadlessContentMainDelegate::CreateContentBrowserClient() {
   browser_client_.reset(new HeadlessContentBrowserClient(browser_.get()));
   return browser_client_.get();
 }
 
 }  // namespace headless