Add a global on/off switch for content settings and expose a toggle on the Website Settings options…

chrome/browser/content_settings/content_settings_override_provider.cc

Index: chrome/browser/content_settings/content_settings_override_provider.cc
diff --git a/chrome/browser/content_settings/content_settings_override_provider.cc b/chrome/browser/content_settings/content_settings_override_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8470f939dcd23edea3189cb904dd66492ecd73ad
--- /dev/null
+++ b/chrome/browser/content_settings/content_settings_override_provider.cc
@@ -0,0 +1,136 @@
+// 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 "chrome/browser/content_settings/content_settings_override_provider.h"
+
+#include <string>
+
+#include "base/auto_reset.h"
+#include "base/prefs/pref_service.h"
+#include "base/prefs/scoped_user_pref_update.h"
+#include "base/values.h"
+#include "chrome/browser/content_settings/content_settings_rule.h"
+#include "chrome/browser/content_settings/content_settings_utils.h"
+#include "chrome/common/content_settings.h"
+#include "chrome/common/pref_names.h"
+#include "components/content_settings/core/common/content_settings_pattern.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace content_settings {
+
+namespace {
+
+class OverrideRuleIterator : public RuleIterator {
+ public:
+  explicit OverrideRuleIterator(bool is_allowed) : is_done_(is_allowed) {}
+
+  virtual bool HasNext() const OVERRIDE { return !is_done_; }
+
+  virtual Rule Next() OVERRIDE {
+    DCHECK(!is_done_);
+    is_done_ = true;
+    return Rule(ContentSettingsPattern::Wildcard(),
+                ContentSettingsPattern::Wildcard(),
+                new base::FundamentalValue(CONTENT_SETTING_BLOCK));
+  }
+
+ private:
+  bool is_done_;
+};
+
+}  // namespace
+
+// static
+void OverrideProvider::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterDictionaryPref(
+      prefs::kOverrideContentSettings,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+}
+
+OverrideProvider::OverrideProvider(PrefService* prefs, bool incognito)
+    : prefs_(prefs), is_incognito_(incognito) {
+  DCHECK(prefs_);
+
+  // Read global overrides.
+  ReadOverrideSettings();
+}
+
+OverrideProvider::~OverrideProvider() {
+}
+
+RuleIterator* OverrideProvider::GetRuleIterator(
+    ContentSettingsType content_type,
+    const ResourceIdentifier& resource_identifier,
+    bool incognito) const {
+  base::AutoLock lock(lock_);
+  if (resource_identifier.empty()) {
+    return new OverrideRuleIterator(allowed_settings_[content_type]);
+  }
+  return new EmptyRuleIterator();
+}
+
+void OverrideProvider::ClearAllContentSettingsRules(
+    ContentSettingsType content_type) {
+}
+
+bool OverrideProvider::SetWebsiteSetting(
+    const ContentSettingsPattern& primary_pattern,
+    const ContentSettingsPattern& secondary_pattern,
+    ContentSettingsType content_type,
+    const ResourceIdentifier& resource_identifier,
+    base::Value* in_value) {
+  return false;
+}
+
+void OverrideProvider::ShutdownOnUIThread() {
+  DCHECK(prefs_);
+  prefs_ = NULL;
+}
+
+void OverrideProvider::SetOverrideSetting(ContentSettingsType content_type,
+                                          bool enabled) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(prefs_);
+
+  // Disallow incognito to change the state.
+  DCHECK(!is_incognito_);
+
+  base::AutoLock lock(lock_);
+  DictionaryPrefUpdate update(prefs_, prefs::kOverrideContentSettings);
+  base::DictionaryValue* default_settings_dictionary = update.Get();
+  if (enabled) {
+    allowed_settings_[content_type] = true;
+    default_settings_dictionary->RemoveWithoutPathExpansion(
+        GetTypeName(content_type), NULL);
+  } else {
+    allowed_settings_[content_type] = false;
+    default_settings_dictionary->SetWithoutPathExpansion(
+        GetTypeName(content_type), new base::FundamentalValue(true));
+  }
+}
+
+bool OverrideProvider::IsEnabled(ContentSettingsType content_type) const {
+  base::AutoLock lock(lock_);
+  return allowed_settings_[content_type];
+}
+
+void OverrideProvider::ReadOverrideSettings() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  const base::DictionaryValue* blocked_settings_dictionary =
+      prefs_->GetDictionary(prefs::kOverrideContentSettings);
+
+  for (int type = 0; type < CONTENT_SETTINGS_NUM_TYPES; ++type) {
+    ContentSettingsType content_setting = ContentSettingsType(type);
+    if (blocked_settings_dictionary->HasKey(GetTypeName(content_setting)))
+      allowed_settings_[content_setting] = false;

[Bernhard Bauer, 2014/09/12 17:16:36]

I would probably directly assign !dictionary->HasKey(...).

[Daniel Nishi, 2014/09/12 19:51:43]

Done.

+    else
+      allowed_settings_[content_setting] = true;
+  }
+}
+
+}  // namespace content_settings