Log error in ValueStore if JSON serialization during writing fails.

For example, this error occurs if one tries to store a base::BinaryValue.

BUG=NONE

Review URL: https://codereview.chromium.org/326393002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@277413 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 9 insertions, 3 deletions

diff --git a/extensions/browser/value_store/leveldb_value_store.cc b/extensions/browser/value_store/leveldb_value_store.cc
index 0f09f5b..6d7fdc9 100644
--- a/extensions/browser/value_store/leveldb_value_store.cc
+++ b/extensions/browser/value_store/leveldb_value_store.cc
@@ -22,6 +22,7 @@ using content::BrowserThread;
 namespace {
 
 const char kInvalidJson[] = "Invalid JSON";
+const char kCannotSerialize[] = "Cannot serialize value to JSON";
 
 // Scoped leveldb snapshot which releases the snapshot on destruction.
 class ScopedSnapshot {
@@ -390,7 +391,8 @@ scoped_ptr<ValueStore::Error> LeveldbValueStore::AddToBatch(
 
   if (write_new_value) {
     std::string value_as_json;
-    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_frontend.cc b/extensions/browser/value_store/value_store_frontend.cc
index 73b6aff..58318c3 100644
--- a/extensions/browser/value_store/value_store_frontend.cc
+++ b/extensions/browser/value_store/value_store_frontend.cc
@@ -55,8 +55,12 @@ class ValueStoreFrontend::Backend : public base::RefCountedThreadSafe<Backend> {
   void Set(const std::string& key, scoped_ptr<base::Value> value) {
     DCHECK_CURRENTLY_ON(BrowserThread::FILE);
     // We don't need the old value, so skip generating changes.
-    storage_->Set(ValueStore::IGNORE_QUOTA | ValueStore::NO_GENERATE_CHANGES,
-                  key, *value.get());
+    ValueStore::WriteResult result = storage_->Set(
+        ValueStore::IGNORE_QUOTA | ValueStore::NO_GENERATE_CHANGES,
+        key,
+        *value.get());
+    LOG_IF(ERROR, result->HasError()) << "Error while writing " << key << " to "
+                                      << db_path_.value();
   }
 
   void Remove(const std::string& key) {