base: Remove the string logging from CHECK().

components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc

Index: components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc
diff --git a/components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc b/components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc
index decea55998e14bf19fe273db197bd365098b5b22..8a29ba5fcb45e9c11fb08b3ce0668295703cb5dc 100644
--- a/components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc
+++ b/components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc
@@ -33,16 +33,16 @@ std::unique_ptr<LoopbackServerEntity> PersistentPermanentEntity::Create(
     const string& server_tag,
     const string& name,
     const string& parent_server_tag) {
-  CHECK(model_type != syncer::UNSPECIFIED) << "The entity's ModelType is "
-                                           << "invalid.";
-  CHECK(!server_tag.empty())
-      << "A PersistentPermanentEntity must have a server tag.";
-  CHECK(!name.empty()) << "The entity must have a non-empty name.";
-  CHECK(!parent_server_tag.empty())
-      << "A PersistentPermanentEntity must have a parent "
-      << "server tag.";
-  CHECK(parent_server_tag != kRootParentTag) << "Top-level entities should not "
-                                             << "be created with this factory.";
+  // The entity's ModelType is invalid.
+  CHECK(model_type != syncer::UNSPECIFIED);
+  // A PersistentPermanentEntity must have a server tag.
+  CHECK(!server_tag.empty());
+  // The entity must have a non-empty name.
+  CHECK(!name.empty());
+  // A PersistentPermanentEntity must have a parent server tag.
+  CHECK(!parent_server_tag.empty());
+  // Top-level entities should not be created with this factory.
+  CHECK(parent_server_tag != kRootParentTag);
 
   string id = LoopbackServerEntity::CreateId(model_type, server_tag);
   string parent_id =
@@ -56,8 +56,8 @@ std::unique_ptr<LoopbackServerEntity> PersistentPermanentEntity::Create(
 // static
 std::unique_ptr<LoopbackServerEntity> PersistentPermanentEntity::CreateTopLevel(
     const ModelType& model_type) {
-  CHECK(model_type != syncer::UNSPECIFIED) << "The entity's ModelType is "
-                                           << "invalid.";
+  // The entity's ModelType is invalid.
+  CHECK(model_type != syncer::UNSPECIFIED);
   string server_tag = syncer::ModelTypeToRootTag(model_type);
   string name = syncer::ModelTypeToString(model_type);
   string id = LoopbackServerEntity::GetTopLevelId(model_type);
@@ -73,8 +73,8 @@ PersistentPermanentEntity::CreateUpdatedNigoriEntity(
     const sync_pb::SyncEntity& client_entity,
     const LoopbackServerEntity& current_server_entity) {
   ModelType model_type = current_server_entity.GetModelType();
-  CHECK(model_type == syncer::NIGORI) << "This factory only supports NIGORI "
-                                      << "entities.";
+  // This factory only supports NIGORI entities.
+  CHECK(model_type == syncer::NIGORI);
 
   return base::WrapUnique<LoopbackServerEntity>(new PersistentPermanentEntity(
       current_server_entity.GetId(), current_server_entity.GetVersion(),