Change configuration of user prefs to use mojo.

services/preferences/public/interfaces/preferences.mojom

Index: services/preferences/public/interfaces/preferences.mojom
diff --git a/services/preferences/public/interfaces/preferences.mojom b/services/preferences/public/interfaces/preferences.mojom
index f3e140956b3e4c8788718fc2af0cc2ae3855cad2..fe32adc3a067f165abbde0eef97e9383718c8f55 100644
--- a/services/preferences/public/interfaces/preferences.mojom
+++ b/services/preferences/public/interfaces/preferences.mojom
@@ -4,7 +4,10 @@
 
 module prefs.mojom;
 
+import "mojo/common/file_path.mojom";
+import "mojo/common/string16.mojom";
 import "mojo/common/values.mojom";
+import "services/preferences/public/interfaces/tracked_preference_validation_delegate.mojom";
 
 const string kServiceName = "preferences";
 
@@ -58,3 +61,57 @@ interface PersistentPrefStoreConnector {
       mojo.common.mojom.DictionaryValue? preferences,
       PersistentPrefStore? pref_store);
 };
+
+interface ResetOnLoadObserver {
+  OnResetOnLoad();
+};
+
+interface PersistentPrefStoreInit {
+  Init(UserPrefsConfiguration configuration);
+};
+
+union UserPrefsConfiguration {
+  SimpleUserPrefsConfiguration simple_configuration;
+  SegregatedUserPrefsConfiguration segregated_configuration;
+};
+
+struct SimpleUserPrefsConfiguration {
+  mojo.common.mojom.FilePath pref_filename;
+};
+
+struct SegregatedUserPrefsConfiguration {
+  mojo.common.mojom.FilePath unprotected_pref_filename;
+  mojo.common.mojom.FilePath protected_pref_filename;
+  array<TrackedPreferenceMetadata> tracking_configuration;
+  uint64 reporting_ids_count;
+  string seed;
+  string legacy_device_id;
+  mojo.common.mojom.String16 registry_path;
+  TrackedPreferenceValidationDelegate? validation_delegate;
+  ResetOnLoadObserver reset_on_load_observer;
+};
+
+struct TrackedPreferenceMetadata {
+  enum EnforcementLevel { NO_ENFORCEMENT, ENFORCE_ON_LOAD };
+
+  enum PrefTrackingStrategy {
+    // Atomic preferences are tracked as a whole.
+    ATOMIC,
+    // Split preferences are dictionaries for which each top-level entry is
+    // tracked independently. Note: preferences using this strategy must be kept
+    // in sync with TrackedSplitPreferences in histograms.xml.
+    SPLIT,
+  };
+
+  enum ValueType {
+    IMPERSONAL,
+    // The preference value may contain personal information.
+    PERSONAL,
+  };
+
+  uint64 reporting_id;
+  string name;
+  EnforcementLevel enforcement_level;
+  PrefTrackingStrategy strategy;
+  ValueType value_type;
+};