Add the basic code skeleton for system info event router

chrome/browser/extensions/mock_system_info_watcher.cc

Index: chrome/browser/extensions/mock_system_info_watcher.cc
diff --git a/chrome/browser/extensions/mock_system_info_watcher.cc b/chrome/browser/extensions/mock_system_info_watcher.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ed0f2b019d1ab5676fb0bbae2e45232f4483321d
--- /dev/null
+++ b/chrome/browser/extensions/mock_system_info_watcher.cc
@@ -0,0 +1,69 @@
+// 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 "chrome/browser/extensions/mock_system_info_watcher.h"
+
+#include "chrome/browser/extensions/event_names.h"
+
+namespace extensions {
+
+namespace {
+
+const int kDefaultInterval = 200; // default interval is 200ms.
+const int kAvailableCapacityBase = 10000;
+const int kChangeStep = 10;
+
+}
+
+MockSystemInfoWatcher::MockSystemInfoWatcher() {
+}
+
+MockSystemInfoWatcher::~MockSystemInfoWatcher() {
+}
+
+bool MockSystemInfoWatcher::PlatformStartWatching(
+    const std::string& event_name) {
+  // If the |event_name| event is already watched.
+  if (IsWatching(event_name))
+    return true;
+
+  if (event_name.compare(
+          event_names::kOnStorageAvailableCapacityChanged) == 0) {
+    // Start the timer to emulate storage.onChanged event.
+    timer_.Start(FROM_HERE,
+                 base::TimeDelta::FromMilliseconds(kDefaultInterval),
+                 this, &MockSystemInfoWatcher::OnTimeoutEvent);
+  }
+  return true;
+}
+
+bool MockSystemInfoWatcher::PlatformStopWatching(
+    const std::string& event_name) {
+  if (!IsWatching(event_name))
+    return false;
+
+  if (event_name.compare(
+          event_names::kOnStorageAvailableCapacityChanged) == 0) {
+    timer_.Stop();
+  }
+  return true;
+}
+
+void MockSystemInfoWatcher::OnTimeoutEvent() {
+  static int count = 0;
+
+  FOR_EACH_OBSERVER(Observer, observers_,
+      OnStorageDeviceAvailableCapacityChanged("/dev/sda1",
+          kAvailableCapacityBase - kChangeStep*count));
+
+  FOR_EACH_OBSERVER(Observer, observers_,
+      OnStorageDeviceAdded("/dev/sda2", "removable", 4096, 2048));
+
+  FOR_EACH_OBSERVER(Observer, observers_,
+      OnStorageDeviceRemoved("/dev/sda2"));
+
+  ++count;
+}
+
+}  // namespace extensions