Write last_modified date to Content Settings in the PrefProvider

components/content_settings/core/browser/content_settings_pref.cc

Index: components/content_settings/core/browser/content_settings_pref.cc
diff --git a/components/content_settings/core/browser/content_settings_pref.cc b/components/content_settings/core/browser/content_settings_pref.cc
index f32e3018b4cc0828d4b5b7efa7a596d5f022d82b..051bf86cb102893f0c932a259d59e7a85e83a857 100644
--- a/components/content_settings/core/browser/content_settings_pref.cc
+++ b/components/content_settings/core/browser/content_settings_pref.cc
@@ -9,6 +9,7 @@
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "components/content_settings/core/browser/content_settings_info.h"
 #include "components/content_settings/core/browser/content_settings_registry.h"
@@ -24,6 +25,7 @@
 namespace {
 
 const char kSettingPath[] = "setting";
+const char kLastModifiedPath[] = "last_modified";
 const char kPerResourceIdentifierPrefName[] = "per_resource";
 
 // If the given content type supports resource identifiers in user preferences,
@@ -61,12 +63,14 @@ ContentSettingsPref::ContentSettingsPref(
     PrefChangeRegistrar* registrar,
     const std::string& pref_name,
     bool incognito,
+    bool store_last_modified,
     NotifyObserversCallback notify_callback)
     : content_type_(content_type),
       prefs_(prefs),
       registrar_(registrar),
       pref_name_(pref_name),
       is_incognito_(incognito),
+      store_last_modified_(store_last_modified),
       updating_preferences_(false),
       notify_callback_(notify_callback) {
   DCHECK(prefs_);
@@ -111,15 +115,15 @@ bool ContentSettingsPref::SetWebsiteSetting(
   if (!is_incognito_)
     map_to_modify = &value_map_;
 
+  base::Time modified_time =
+      store_last_modified_ ? base::Time::Now() : base::Time();
+
   {
     base::AutoLock auto_lock(lock_);
     if (value.get()) {
-      map_to_modify->SetValue(
-          primary_pattern,
-          secondary_pattern,
-          content_type_,
-          resource_identifier,
-          value->DeepCopy());
+      map_to_modify->SetValue(primary_pattern, secondary_pattern, content_type_,
+                              resource_identifier, modified_time,
+                              value->DeepCopy());
     } else {
       map_to_modify->DeleteValue(
           primary_pattern,
@@ -130,10 +134,8 @@ bool ContentSettingsPref::SetWebsiteSetting(
   }
   // Update the content settings preference.
   if (!is_incognito_) {
-    UpdatePref(primary_pattern,
-               secondary_pattern,
-               resource_identifier,
-               value.get());
+    UpdatePref(primary_pattern, secondary_pattern, resource_identifier,
+               modified_time, value.get());
   }
 
   notify_callback_.Run(
@@ -240,6 +242,14 @@ void ContentSettingsPref::ReadContentSettingsFromPref() {
     bool is_dictionary = i.value().GetAsDictionary(&settings_dictionary);
     DCHECK(is_dictionary);
 
+    // Get last modified timestamp.

[msramek, 2017/04/19 10:49:16]

We're using one last modified timestamp per pattern pair, regardless of resource
identifiers. As discussed offline, I'm fine with that to avoid complexity, since
the only downside is that deletion of content settings would reset all plugins
on a page where you recently changed the setting for one of them.

...if that even works after all the Flash changes. I have a vague memory that
Raymes was about to remove those.

However, please comment on that :)

[dullweber, 2017/04/19 15:02:45]

I just changed it to store a timestamp per resource but if the whole
per-resource settings can be removed anyway that would be much better.

[raymes, 2017/04/20 00:10:13]

I think we'd like to remove the per-resource identifiers. I think they're not
really used by anything anymore. We just need to get around to doing it.

+    std::string time_stamp_str;
+    settings_dictionary->GetStringWithoutPathExpansion(kLastModifiedPath,
+                                                       &time_stamp_str);
+    int64_t time_stamp = 0;
+    base::StringToInt64(time_stamp_str, &time_stamp);
+    base::Time last_modified = base::Time::FromInternalValue(time_stamp);
+
     if (SupportsResourceIdentifiers(content_type_)) {
       const base::DictionaryValue* resource_dictionary = NULL;
       if (settings_dictionary->GetDictionary(
@@ -253,10 +263,8 @@ void ContentSettingsPref::ReadContentSettingsFromPref() {
           DCHECK(is_integer);
           DCHECK_NE(CONTENT_SETTING_DEFAULT, setting);
           std::unique_ptr<base::Value> setting_ptr(new base::Value(setting));
-          value_map_.SetValue(pattern_pair.first,
-                              pattern_pair.second,
-                              content_type_,
-                              resource_identifier,
+          value_map_.SetValue(pattern_pair.first, pattern_pair.second,
+                              content_type_, resource_identifier, last_modified,
                               setting_ptr->DeepCopy());
         }
       }
@@ -264,13 +272,10 @@ void ContentSettingsPref::ReadContentSettingsFromPref() {
 
     const base::Value* value = nullptr;
     settings_dictionary->GetWithoutPathExpansion(kSettingPath, &value);
-
     if (value) {
       DCHECK(IsValueAllowedForType(value, content_type_));
-      value_map_.SetValue(pattern_pair.first,
-                          pattern_pair.second,
-                          content_type_,
-                          ResourceIdentifier(),
+      value_map_.SetValue(pattern_pair.first, pattern_pair.second,
+                          content_type_, ResourceIdentifier(), last_modified,
                           value->DeepCopy());
       if (content_type_ == CONTENT_SETTINGS_TYPE_COOKIES) {
         ContentSetting s = ValueToContentSetting(value);
@@ -321,6 +326,7 @@ void ContentSettingsPref::UpdatePref(
     const ContentSettingsPattern& primary_pattern,
     const ContentSettingsPattern& secondary_pattern,
     const ResourceIdentifier& resource_identifier,
+    const base::Time last_modified,
     const base::Value* value) {
   // Ensure that |lock_| is not held by this thread, since this function will
   // send out notifications (by |~DictionaryPrefUpdate|).
@@ -364,18 +370,29 @@ void ContentSettingsPref::UpdatePref(
           if (resource_dictionary->empty()) {
             settings_dictionary->RemoveWithoutPathExpansion(
                 kPerResourceIdentifierPrefName, NULL);
+            settings_dictionary->RemoveWithoutPathExpansion(kLastModifiedPath,
+                                                            NULL);
           }
         } else {
           resource_dictionary->SetWithoutPathExpansion(
               resource_identifier, value->DeepCopy());
+          // Update timestamp for whole resource dictionary.
+          settings_dictionary->SetStringWithoutPathExpansion(
+              kLastModifiedPath,
+              base::Int64ToString(last_modified.ToInternalValue()));
         }
       } else {
         // Update settings dictionary.
         if (value == NULL) {
           settings_dictionary->RemoveWithoutPathExpansion(kSettingPath, NULL);
+          settings_dictionary->RemoveWithoutPathExpansion(kLastModifiedPath,
+                                                          NULL);
         } else {
           settings_dictionary->SetWithoutPathExpansion(
               kSettingPath, value->DeepCopy());
+          settings_dictionary->SetStringWithoutPathExpansion(
+              kLastModifiedPath,
+              base::Int64ToString(last_modified.ToInternalValue()));
         }
       }
       // Remove the settings dictionary if it is empty.