Beginnings of the script bubble.

chrome/common/extensions/feature_switch.cc

Index: chrome/common/extensions/feature_switch.cc
diff --git a/chrome/common/extensions/feature_switch.cc b/chrome/common/extensions/feature_switch.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ed6443e37fb48f4dab9f00db0e8f846bf14ed2bd
--- /dev/null
+++ b/chrome/common/extensions/feature_switch.cc
@@ -0,0 +1,83 @@
+// 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/common/extensions/feature_switch.h"
+
+#include "base/command_line.h"
+#include "base/lazy_instance.h"
+#include "base/string_util.h"
+#include "chrome/common/chrome_switches.h"
+
+namespace extensions {
+
+namespace {
+
+class CommonSwitches {
+ public:
+  CommonSwitches()
+      : script_bubble(CommandLine::ForCurrentProcess(),
+                      switches::kScriptBubbleEnabled,
+                      FeatureSwitch::DEFAULT_DISABLED) {
+  }
+  FeatureSwitch script_bubble;
+};
+
+base::LazyInstance<CommonSwitches> g_common_switches =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+
+FeatureSwitch* FeatureSwitch::GetScriptBubble() {
+  return &g_common_switches.Get().script_bubble;
+}
+
+FeatureSwitch::ScopedOverride::ScopedOverride(FeatureSwitch* feature,
+                                              bool override_value)
+    : feature_(feature) {
+  feature_->SetOverrideValue(
+      override_value ? OVERRIDE_ENABLED : OVERRIDE_DISABLED);
+}
+
+FeatureSwitch::ScopedOverride::~ScopedOverride() {
+  feature_->SetOverrideValue(OVERRIDE_NONE);
+}
+
+FeatureSwitch::FeatureSwitch(const CommandLine* command_line,
+                             const char* switch_name,
+                             DefaultValue default_value)
+    : command_line_(command_line),
+      switch_name_(switch_name),
+      default_value_(default_value == DEFAULT_ENABLED),
+      override_value_(OVERRIDE_NONE) {
+}
+
+bool FeatureSwitch::IsEnabled() const {
+  if (override_value_ != OVERRIDE_NONE)
+    return override_value_ == OVERRIDE_ENABLED;
+
+  // TODO(aa): Consider supporting other values.
+  std::string temp = command_line_->GetSwitchValueASCII(switch_name_);
+  std::string switch_value;
+  TrimWhitespaceASCII(temp, TRIM_ALL, &switch_value);
+  if (switch_value == "1")
+    return true;
+  if (switch_value == "0")
+    return false;
+  return default_value_;
+}
+
+FeatureSwitch::ScopedOverride FeatureSwitch::Override(
+    bool override_value) {
+  return ScopedOverride(this, override_value);
+}
+
+void FeatureSwitch::SetOverrideValue(OverrideValue override_value) {
+  if (override_value_ != OVERRIDE_NONE)
+    CHECK_EQ(OVERRIDE_NONE, override_value);
+
+  override_value_ = override_value;
+}
+
+}  // namespace extensions