Remove NPAPI plugin from chromoting webapp.

remoting/host/plugin/host_log_handler.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 "remoting/host/plugin/host_log_handler.h"
-
-#include "base/lazy_instance.h"
-#include "remoting/base/logging.h"
-#include "remoting/base/util.h"
-#include "remoting/host/plugin/host_script_object.h"
-
-namespace remoting {
-
-// Records whether or not we have a scriptable object registered for logging.
-// This is set inside the lock, but is read (in LogToUI) outside of a lock so
-// that we don't needlessly slow down the system when we log.
-static bool g_has_logging_scriptable_object = false;
-
-// The lock that protects the logging globals.
-static base::LazyInstance<base::Lock>::Leaky
-    g_logging_lock = LAZY_INSTANCE_INITIALIZER;
-
-// The scriptable object that will display the log information to the user.
-static HostNPScriptObject* g_logging_scriptable_object = NULL;
-
-// The previously registered LogMessageHandler. If not NULL, we call this after
-// we're doing processing the log message.
-static logging::LogMessageHandlerFunction g_logging_old_handler = NULL;
-
-// Set to true when we register our global log handler so that we don't try
-// to register it twice.
-static bool g_has_registered_log_handler = false;
-
-// static
-void HostLogHandler::RegisterLogMessageHandler() {
-  base::AutoLock lock(g_logging_lock.Get());
-
-  if (g_has_registered_log_handler)
-    return;
-
-  HOST_LOG << "Registering global log handler";
-
-  // Record previous handler so we can call it in a chain.
-  g_logging_old_handler = logging::GetLogMessageHandler();
-
-  // Set up log message handler.
-  // This is not thread-safe so we need it within our lock.
-  // Note that this will not log anything until a scriptable object instance
-  // has been created to handle the log message display.
-  logging::SetLogMessageHandler(&LogToUI);
-  g_has_registered_log_handler = true;
-}
-
-// static
-void HostLogHandler::RegisterLoggingScriptObject(
-    HostNPScriptObject* script_object) {
-  base::AutoLock lock(g_logging_lock.Get());
-
-  VLOG(1) << "Registering log handler scriptable object";
-
-  // Register this script object as the one that will handle all logging calls
-  // and display them to the user.
-  // If multiple plugins are run, then the last one registered will handle all
-  // logging for all instances.
-  g_logging_scriptable_object = script_object;
-  g_has_logging_scriptable_object = true;
-}
-
-// static
-void HostLogHandler::UnregisterLoggingScriptObject(
-    HostNPScriptObject* script_object) {
-  base::AutoLock lock(g_logging_lock.Get());
-
-  // Ignore unless we're the currently registered script object.
-  if (script_object != g_logging_scriptable_object)
-    return;
-
-  // Unregister this script object for logging.
-  g_has_logging_scriptable_object = false;
-  g_logging_scriptable_object = NULL;
-
-  VLOG(1) << "Unregistering log handler scriptable object";
-}
-
-// static
-bool HostLogHandler::LogToUI(int severity, const char* file, int line,
-                             size_t message_start,
-                             const std::string& str) {
-  // Note: We're reading |g_has_logging_scriptable_object| outside of a lock.
-  // This lockless read is done so that we don't needlessly slow down global
-  // logging with a lock for each log message.
-  //
-  // This lockless read is safe because:
-  //
-  // Misreading a false value (when it should be true) means that we'll simply
-  // skip processing a few log messages.
-  //
-  // Misreading a true value (when it should be false) means that we'll take
-  // the lock and check |g_logging_scriptable_object| unnecessarily. This is not
-  // problematic because we always set |g_logging_scriptable_object| inside a
-  // lock.
-  //
-  // Misreading an old cached value is also not problematic for the same
-  // reasons: a mis-read either skips a log message or causes us to take a lock
-  // unnecessarily.
-  if (g_has_logging_scriptable_object) {
-    base::AutoLock lock(g_logging_lock.Get());
-
-    if (g_logging_scriptable_object) {
-      std::string message = remoting::GetTimestampString();
-      message += (str.c_str() + message_start);
-      g_logging_scriptable_object->PostLogDebugInfo(message);
-    }
-  }
-
-  // Call the next log handler in the chain.
-  if (g_logging_old_handler)
-    return (g_logging_old_handler)(severity, file, line, message_start, str);
-
-  return false;
-}
-
-}  // namespace remoting