diff --git a/src/base/prefs/test/data/pref_service/invalid.json b/src/base/prefs/test/data/pref_service/invalid.json
new file mode 100644
index 0000000..43392a9
--- /dev/null
+++ b/src/base/prefs/test/data/pref_service/invalid.json
@@ -0,0 +1 @@
+!@#$%^&
\ No newline at end of file
diff --git a/src/base/prefs/test/data/pref_service/read.json b/src/base/prefs/test/data/pref_service/read.json
new file mode 100644
index 0000000..ea578a4
--- /dev/null
+++ b/src/base/prefs/test/data/pref_service/read.json
@@ -0,0 +1,8 @@
+{
+  "homepage": "http://www.cnn.com",
+  "some_directory": "/usr/local/",
+  "tabs": {
+    "new_windows_in_tabs": true,
+    "max_tabs": 20
+  }
+}
diff --git a/src/base/prefs/test/data/pref_service/read.need_empty_value.json b/src/base/prefs/test/data/pref_service/read.need_empty_value.json
new file mode 100644
index 0000000..48e1749
--- /dev/null
+++ b/src/base/prefs/test/data/pref_service/read.need_empty_value.json
@@ -0,0 +1,10 @@
+{
+  "list": [ 1 ],
+  "list_needs_empty_value": [ 2 ],
+  "dict": {
+    "dummy": true
+  },
+  "dict_needs_empty_value": {
+    "dummy": true
+  }
+}
diff --git a/src/base/prefs/test/data/pref_service/write.golden.json b/src/base/prefs/test/data/pref_service/write.golden.json
new file mode 100644
index 0000000..9a5523c
--- /dev/null
+++ b/src/base/prefs/test/data/pref_service/write.golden.json
@@ -0,0 +1,11 @@
+{
+   "homepage": "http://www.cnn.com",
+   "long_int": {
+      "pref": "214748364842"
+   },
+   "some_directory": "/usr/sbin/",
+   "tabs": {
+      "max_tabs": 10,
+      "new_windows_in_tabs": false
+   }
+}
diff --git a/src/base/prefs/test/data/pref_service/write.golden.need_empty_value.json b/src/base/prefs/test/data/pref_service/write.golden.need_empty_value.json
new file mode 100644
index 0000000..fa79590
--- /dev/null
+++ b/src/base/prefs/test/data/pref_service/write.golden.need_empty_value.json
@@ -0,0 +1,6 @@
+{
+   "dict_needs_empty_value": {
+
+   },
+   "list_needs_empty_value": [  ]
+}