Add TODO comments

Author: milaGGL

packages/firestore/src/model/path.ts

@@ -163,6 +163,7 @@ abstract class BasePath<B extends BasePath<B>> {
     return this.segments.slice(this.offset, this.limit());
   }
 
+  // TODO(Mila): Use database info and toString() to get full path instead.
   toFullPath(): string {
     return this.segments.join('/');
   }

packages/firestore/src/remote/watch_change.ts

@@ -484,6 +484,7 @@ export class WatchChangeAggregator {
     return expectedCount === currentCount - removedDocumentCount;
   }
 
+  // TODO(Mila): Move the validation into normalizeByteString.
   private isValidBase64String(value: string): boolean {
     const regExp = new RegExp(
       '^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$'