Convert JsonWriter::Write to taking a const ref for the in-param

Clearer API; flushes out a lot of unnecessary heap allocations.

depends on https://codereview.chromium.org/1129083003/

BUG=none

Review URL: https://codereview.chromium.org/1131113004

Cr-Commit-Position: refs/heads/master@{#330255}

3 files changed, 4 insertions, 5 deletions

diff --git a/extensions/browser/value_store/leveldb_value_store.cc b/extensions/browser/value_store/leveldb_value_store.cc
index ad8076d..4b7d274 100644
--- a/extensions/browser/value_store/leveldb_value_store.cc
+++ b/extensions/browser/value_store/leveldb_value_store.cc
@@ -389,7 +389,7 @@ scoped_ptr<ValueStore::Error> LeveldbValueStore::AddToBatch(
 
   if (write_new_value) {
     std::string value_as_json;
-    if (!base::JSONWriter::Write(&value, &value_as_json))
+    if (!base::JSONWriter::Write(value, &value_as_json))
       return Error::Create(OTHER_ERROR, kCannotSerialize, util::NewKey(key));
     batch->Put(key, value_as_json);
   }
diff --git a/extensions/browser/value_store/value_store_change.cc b/extensions/browser/value_store/value_store_change.cc
index 822c9b9..904ec82 100644
--- a/extensions/browser/value_store/value_store_change.cc
+++ b/extensions/browser/value_store/value_store_change.cc
@@ -23,7 +23,7 @@ std::string ValueStoreChange::ToJson(
     changes_value.SetWithoutPathExpansion(it->key(), change_value);
   }
   std::string json;
-  base::JSONWriter::Write(&changes_value, &json);
+  base::JSONWriter::Write(changes_value, &json);
   return json;
 }
 
diff --git a/extensions/browser/value_store/value_store_unittest.cc b/extensions/browser/value_store/value_store_unittest.cc
index 4293459..c2ecbab 100644
--- a/extensions/browser/value_store/value_store_unittest.cc
+++ b/extensions/browser/value_store/value_store_unittest.cc
@@ -18,9 +18,8 @@ const ValueStore::WriteOptions DEFAULTS = ValueStore::DEFAULTS;
 // Gets the pretty-printed JSON for a value.
 std::string GetJSON(const base::Value& value) {
   std::string json;
-  base::JSONWriter::WriteWithOptions(&value,
-                                     base::JSONWriter::OPTIONS_PRETTY_PRINT,
-                                     &json);
+  base::JSONWriter::WriteWithOptions(
+      value, base::JSONWriter::OPTIONS_PRETTY_PRINT, &json);
   return json;
 }