Fix various memory leaks in unit tests detected by a new version of ASAN.

runtime/vm/snapshot_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 
 #include "include/dart_tools_api.h"
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
 #include "vm/clustered_snapshot.h"
@@ skipping 121 matching lines @@
   // Encode and decode the message.
   uint8_t* buffer = NULL;
   ApiMessageWriter writer(&buffer, &malloc_allocator);
   writer.WriteCMessage(root);
 
   ApiMessageReader api_reader(buffer, writer.BytesWritten());
   Dart_CObject* new_root = api_reader.ReadMessage();
 
   // Check that the two messages are the same.
   CompareDartCObjects(root, new_root);
+
+  free(buffer);
 }
 
 
 static void ExpectEncodeFail(Dart_CObject* root) {
   uint8_t* buffer = NULL;
   ApiMessageWriter writer(&buffer, &malloc_allocator);
   const bool result = writer.WriteCMessage(root);
   EXPECT_EQ(false, result);
+  free(buffer);
 }
 
 
 TEST_CASE(SerializeNull) {
   StackZone zone(thread);
 
   // Write snapshot with object content.
   const Object& null_object = Object::Handle();
   uint8_t* buffer;
   MessageWriter writer(&buffer, &zone_allocator, true);
@@ skipping 1486 matching lines @@
   }
 
   {
     // Use a script snapshot where a full snapshot is expected.
     char* error = NULL;
     Dart_Isolate isolate = Dart_CreateIsolate(
         "script-uri", "main", script_snapshot, NULL, NULL, &error);
     EXPECT(isolate == NULL);
     EXPECT(error != NULL);
     EXPECT_SUBSTRING("got 'script', expected 'core'", error);
+    free(error);
   }
 
   {
     TestCase::CreateTestIsolateFromSnapshot(full_snapshot);
     Dart_EnterScope();  // Start a Dart API scope for invoking API functions.
 
     // Use a full snapshot where a script snapshot is expected.
     Dart_Handle result = Dart_LoadScriptFromSnapshot(full_snapshot, size);
     EXPECT_ERROR(result,
                  "Dart_LoadScriptFromSnapshot expects parameter"
@@ skipping 1321 matching lines @@
   StackZone zone(Thread::Current());
   uint8_t* buffer;
   MessageWriter writer(&buffer, &zone_allocator, true);
   writer.WriteInlinedObjectHeader(kOmittedObjectId);
   // For performance, we'd like single-byte headers when ids are omitted.
   // If this starts failing, consider renumbering the snapshot ids.
   EXPECT_EQ(1, writer.BytesWritten());
 }
 
 }  // namespace dart