headless: Add command line flags for logging

headless/app/headless_shell.cc

Index: headless/app/headless_shell.cc
diff --git a/headless/app/headless_shell.cc b/headless/app/headless_shell.cc
index cd05f9796cec82027c032dfc5a6fdf020d309db9..43d344c19f1af1b84ea4fadcafecf715d3a60c0d 100644
--- a/headless/app/headless_shell.cc
+++ b/headless/app/headless_shell.cc
@@ -17,6 +17,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/numerics/safe_conversions.h"
+#include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "content/public/common/content_switches.h"
 #include "headless/app/headless_shell_switches.h"
@@ -436,13 +437,58 @@ bool ValidateCommandLine(const base::CommandLine& command_line) {
   return true;
 }
 
+void InitLogging(const base::CommandLine& command_line) {
+  if (!command_line.HasSwitch(switches::kEnableLogging))
+    return;
+
+  logging::LoggingDestination log_mode;
+  if (command_line.GetSwitchValueASCII(switches::kEnableLogging) == "stderr") {
+    log_mode = logging::LOG_TO_SYSTEM_DEBUG_LOG;
+  } else {
+    log_mode = logging::LOG_TO_ALL;
+  }
+
+  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;
+    }
+  }
+
+  const base::FilePath log_filename(FILE_PATH_LITERAL("chrome_debug.log"));

[altimin, 2017/02/02 22:44:45]

Let's make output file configurable. We can use value of kEnableLogging switch.

[Sami, 2017/02/02 23:15:33]

Done.

+  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;
+  bool success = logging::InitLogging(settings);
+  DCHECK(success);
+}
+
 int HeadlessShellMain(int argc, const char** argv) {
   RunChildProcessIfNeeded(argc, argv);
   HeadlessShell shell;
   HeadlessBrowser::Options::Builder builder(argc, argv);
 
   // Enable devtools if requested.
-  base::CommandLine command_line(argc, argv);
+  base::CommandLine::Init(argc, argv);
+  const base::CommandLine& command_line(
+      *base::CommandLine::ForCurrentProcess());
+  InitLogging(command_line);
   if (!ValidateCommandLine(command_line))
     return EXIT_FAILURE;