Disable Web Notifications in Incognito

chrome/browser/permissions/permission_context_base.cc

Index: chrome/browser/permissions/permission_context_base.cc
diff --git a/chrome/browser/permissions/permission_context_base.cc b/chrome/browser/permissions/permission_context_base.cc
index fccd23005ca9d88386be7974a8d2d6555e1cfbe1..41b38b06d516e504c25fc9d37ed881198d9e64a7 100644
--- a/chrome/browser/permissions/permission_context_base.cc
+++ b/chrome/browser/permissions/permission_context_base.cc
@@ -5,11 +5,18 @@
 #include "chrome/browser/permissions/permission_context_base.h"
 
 #include <stddef.h>
+
+#include <queue>
 #include <utility>
 
+#include "base/location.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
+#include "base/rand_util.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
+#include "base/thread_task_runner_handle.h"
+#include "base/timer/timer.h"
 #include "build/build_config.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/permissions/permission_request_id.h"
@@ -17,12 +24,16 @@
 #include "chrome/browser/permissions/permission_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
+#include "components/content_settings/core/browser/content_settings_info.h"
+#include "components/content_settings/core/browser/content_settings_registry.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/browser/website_settings_registry.h"
 #include "components/variations/variations_associated_data.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
 #include "content/public/common/origin_util.h"
 
 #if defined(OS_ANDROID)
@@ -32,6 +43,105 @@
 #include "chrome/browser/ui/website_settings/permission_bubble_manager.h"
 #endif
 
+namespace {
+
+// At most one of these is attached to each WebContents.
+class VisibilityTimerTabHelper
+    : public content::WebContentsObserver,
+      public content::WebContentsUserData<VisibilityTimerTabHelper> {
+ public:
+  ~VisibilityTimerTabHelper() override {};
+
+  // Runs |task| after the WebContents has been visible for a consecutive
+  // duration of at least |visible_delay|.
+  void PostTaskAfterVisibleDelay(const tracked_objects::Location& from_here,
+                                 const base::Closure& task,
+                                 base::TimeDelta visible_delay);
+
+  // WebContentsObserver:
+  void WasShown() override;
+  void WasHidden() override;
+  void WebContentsDestroyed() override;
+
+ private:
+  friend class content::WebContentsUserData<VisibilityTimerTabHelper>;
+  explicit VisibilityTimerTabHelper(content::WebContents* contents);
+
+  void RunTask(const base::Closure& task);
+
+  bool is_visible_;
+  std::queue<scoped_ptr<base::Timer>> task_queue_;
+
+  DISALLOW_COPY_AND_ASSIGN(VisibilityTimerTabHelper);
+};
+
+VisibilityTimerTabHelper::VisibilityTimerTabHelper(
+    content::WebContents* contents)
+    : content::WebContentsObserver(contents) {
+  if (!contents->GetMainFrame()) {
+    is_visible_ = false;
+  } else {
+    switch (contents->GetMainFrame()->GetVisibilityState()) {
+      case blink::WebPageVisibilityStateHidden:
+      case blink::WebPageVisibilityStatePrerender:
+        is_visible_ = false;
+        break;
+      case blink::WebPageVisibilityStateVisible:
+        is_visible_ = true;
+        break;
+    }
+  }
+}
+
+void VisibilityTimerTabHelper::PostTaskAfterVisibleDelay(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeDelta visible_delay) {
+  // Safe to use Unretained, as destroying this will destroy task_queue_, hence
+  // cancelling all timers.
+  task_queue_.push(make_scoped_ptr(new base::Timer(
+      from_here, visible_delay, base::Bind(&VisibilityTimerTabHelper::RunTask,
+                                           base::Unretained(this), task),
+      false /* is_repeating */)));
+  DCHECK(!task_queue_.back()->IsRunning());
+  if (is_visible_ && task_queue_.size() == 1)
+    task_queue_.front()->Reset();
+}
+
+void VisibilityTimerTabHelper::WasShown() {
+  if (!is_visible_ && !task_queue_.empty())
+    task_queue_.front()->Reset();
+  is_visible_ = true;
+}
+
+void VisibilityTimerTabHelper::WasHidden() {
+  if (is_visible_ && !task_queue_.empty())
+    task_queue_.front()->Stop();
+  is_visible_ = false;
+}
+
+void VisibilityTimerTabHelper::WebContentsDestroyed() {
+  // Delete ourselves, to avoid running tasks after WebContents is destroyed.
+  web_contents()->RemoveUserData(UserDataKey());
+  // |this| has been deleted now.
+}
+
+void VisibilityTimerTabHelper::RunTask(const base::Closure& task) {
+  DCHECK(is_visible_);
+  task.Run();
+  task_queue_.pop();
+  if (!task_queue_.empty()) {
+    task_queue_.front()->Reset();
+    return;
+  }
+  web_contents()->RemoveUserData(UserDataKey());
+  // |this| has been deleted now.
+}
+
+}  // namespace
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(VisibilityTimerTabHelper);
+
 // static
 const char PermissionContextBase::kPermissionsKillSwitchFieldStudy[] =
     "PermissionsKillSwitch";
@@ -169,6 +279,31 @@ void PermissionContextBase::DecidePermission(
     const BrowserPermissionCallback& callback) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
+  // Some permissions are always denied in incognito. To prevent sites from
+  // using these to detect whether incognito mode is active, we deny after a
+  // random time delay, to simulate a user clicking a bubble/infobar.
+  if (profile()->IsOffTheRecord()) {
+    const content_settings::ContentSettingsInfo* info =
+        content_settings::ContentSettingsRegistry::GetInstance()->Get(
+            content_settings_type_);
+    if (info &&
+        info->incognito_behavior() == content_settings::ContentSettingsInfo::
+                                          DENY_IN_INCOGNITO_AFTER_DELAY) {
+      // Random number of seconds in the range [1.0, 2.0).
+      double delay_seconds = 1.0 + 1.0 * base::RandDouble();
+      VisibilityTimerTabHelper::CreateForWebContents(web_contents);
+      VisibilityTimerTabHelper::FromWebContents(web_contents)
+          ->PostTaskAfterVisibleDelay(
+              FROM_HERE,
+              base::Bind(&PermissionContextBase::NotifyPermissionSet,
+                         weak_factory_.GetWeakPtr(), id, requesting_origin,
+                         embedding_origin, callback, true /* persist */,
+                         CONTENT_SETTING_BLOCK),
+              base::TimeDelta::FromSecondsD(delay_seconds));
+      return;
+    }
+  }
+
 #if !defined(OS_ANDROID)
   PermissionBubbleManager* bubble_manager =
       PermissionBubbleManager::FromWebContents(web_contents);