Log device/hid messages to chrome://device-log.

components/device_event_log/device_event_log.cc

 // Copyright 2014 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 "components/device_event_log/device_event_log.h"
 
 #include <string>
 
 #include "base/logging.h"
 #include "components/device_event_log/device_event_log_impl.h"
@@ skipping 66 matching lines @@
                                                int line,
                                                device_event_log::LogType type,
                                                device_event_log::LogLevel level)
     : file_(file), line_(line), type_(type), level_(level) {
 }
 
 DeviceEventLogInstance::~DeviceEventLogInstance() {
   device_event_log::AddEntry(file_, line_, type_, level_, stream_.str());
 }
 
+DeviceEventSystemErrorLogInstance::DeviceEventSystemErrorLogInstance(
+    const char* file,
+    int line,
+    device_event_log::LogType type,
+    device_event_log::LogLevel level,
+    logging::SystemErrorCode err)
+    : err_(err), log_instance_(file, line, type, level) {
+}
+
+DeviceEventSystemErrorLogInstance::~DeviceEventSystemErrorLogInstance() {
+  stream() << ": " << ::logging::SystemErrorCodeToString(err_);
+}
+
 ScopedDeviceLogIfSlow::ScopedDeviceLogIfSlow(LogType type,
                                              const char* file,
                                              const std::string& name)
     : file_(file), type_(type), name_(name) {
 }
 
 ScopedDeviceLogIfSlow::~ScopedDeviceLogIfSlow() {
   if (timer_.Elapsed().InMilliseconds() >= kSlowMethodThresholdMs) {
     LogLevel level(LOG_LEVEL_DEBUG);
     if (timer_.Elapsed().InMilliseconds() >= kVerySlowMethodThresholdMs)
       level = LOG_LEVEL_ERROR;
     DEVICE_LOG(type_, level) << "@@@ Slow method: " << file_ << ":" << name_
                              << ": " << timer_.Elapsed().InMilliseconds()
                              << "ms";
   }
 }
 
 }  // namespace internal
 
 }  // namespace device_event_log