Fix OutOfMemoryDeathTest.ViaSharedLibraries.

This test was invalid on modern glibc:
asprintf errors EOVERFLOW without attempting an allocation
when the size is at least INT_MAX - 32. INT_MAX - 33 is the
largest size that can attempt to trigger allocation failure,
and will not necessarily accomplish that on some systems.

Create a library that is specified to wrap malloc trivially,
to accomplish the goal of the test without external dependencies
or inconsistently implemented behavior.

BUG=428211

Review URL: https://codereview.chromium.org/878473002

Cr-Commit-Position: refs/heads/master@{#323197}

3 files changed, 42 insertions, 0 deletions

diff --git a/base/test/BUILD.gn b/base/test/BUILD.gn
index c4356cb..b94a4c7 100644
--- a/base/test/BUILD.gn
+++ b/base/test/BUILD.gn
@@ -183,6 +183,16 @@ source_set("run_all_unittests") {
   ]
 }
 
+shared_library("malloc_wrapper") {
+  testonly = true
+  sources = [
+    "malloc_wrapper.cc",
+  ]
+  deps = [
+    "//base",
+  ]
+}
+
 if (is_android) {
   generate_jni("base_unittests_jni_headers") {
     sources = [
diff --git a/base/test/malloc_wrapper.cc b/base/test/malloc_wrapper.cc
new file mode 100644
index 0000000..eb280a3
--- /dev/null
+++ b/base/test/malloc_wrapper.cc
@@ -0,0 +1,11 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "malloc_wrapper.h"
+
+#include <stdlib.h>
+
+void* MallocWrapper(size_t size) {
+  return malloc(size);
+}
diff --git a/base/test/malloc_wrapper.h b/base/test/malloc_wrapper.h
new file mode 100644
index 0000000..0fa7dbb
--- /dev/null
+++ b/base/test/malloc_wrapper.h
@@ -0,0 +1,21 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_TEST_MALLOC_WRAPPER_H_
+#define BASE_TEST_MALLOC_WRAPPER_H_
+
+#include "base/basictypes.h"
+
+// BASE_EXPORT depends on COMPONENT_BUILD.
+// This will always be a separate shared library, so don't use BASE_EXPORT here.
+#if defined(WIN32)
+#define MALLOC_WRAPPER_EXPORT __declspec(dllexport)
+#else
+#define MALLOC_WRAPPER_EXPORT __attribute__((visibility("default")))
+#endif  // defined(WIN32)
+
+// Calls malloc directly.
+MALLOC_WRAPPER_EXPORT void* MallocWrapper(size_t size);
+
+#endif  // BASE_TEST_MALLOC_WRAPPER_H_