Handlification TODOs in scanner and string stream resolved.

src/scanner.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include <cmath>
 
 #include "scanner.h"
 
@@ skipping 1077 matching lines @@
   }
   literal.Complete();
 
   next_.location.end_pos = source_pos() - 1;
   return true;
 }
 
 
 Handle<String> Scanner::AllocateNextLiteralString(Isolate* isolate,
                                                   PretenureFlag tenured) {
-  MaybeHandle<String> maybe_result;
   if (is_next_literal_one_byte()) {
-    maybe_result = isolate->factory()->NewStringFromOneByte(
-        next_literal_one_byte_string(), tenured);
+    return isolate->factory()->NewStringFromOneByte(
+        next_literal_one_byte_string(), tenured).ToHandleChecked();
   } else {
-    maybe_result = isolate->factory()->NewStringFromTwoByte(
-        next_literal_two_byte_string(), tenured);
+    return isolate->factory()->NewStringFromTwoByte(
+        next_literal_two_byte_string(), tenured).ToHandleChecked();
   }
-  // TODO(ishell): Temporarily returning null handle from here. I will proceed
-  // with maybehandlification in next CLs.
-  Handle<String> result;
-  if (!maybe_result.ToHandle(&result)) return Handle<String>();
-  return result;
 }
 
 
 Handle<String> Scanner::AllocateInternalizedString(Isolate* isolate) {
   if (is_literal_one_byte()) {
     return isolate->factory()->InternalizeOneByteString(
         literal_one_byte_string());
   } else {
     return isolate->factory()->InternalizeTwoByteString(
         literal_two_byte_string());
@@ skipping 165 matching lines @@
     }
     backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u));
   }
   backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f));
 
   backing_store_.AddBlock(bytes);
   return backing_store_.EndSequence().start();
 }
 
 } }  // namespace v8::internal