[icu] Support loading data file from default location

src/startup-data-util.cc

 // Copyright 2015 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.
 
 #include "src/startup-data-util.h"
 
 #include <stdlib.h>
 #include <string.h>
 
+#include "src/base/file-utils.h"
 #include "src/base/logging.h"
 #include "src/base/platform/platform.h"
 #include "src/utils.h"
 
 
 namespace v8 {
 namespace internal {
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
 
@@ skipping 50 matching lines @@
 }
 
 
 void LoadFromFiles(const char* natives_blob, const char* snapshot_blob) {
   Load(natives_blob, &g_natives, v8::V8::SetNativesDataBlob);
   Load(snapshot_blob, &g_snapshot, v8::V8::SetSnapshotDataBlob);
 
   atexit(&FreeStartupData);
 }
 
-
-char* RelativePath(char** buffer, const char* exec_path, const char* name) {
-  DCHECK(exec_path);
-  int path_separator = static_cast<int>(strlen(exec_path)) - 1;
-  while (path_separator >= 0 &&
-         !base::OS::isDirectorySeparator(exec_path[path_separator])) {
-    path_separator--;
-  }
-  if (path_separator >= 0) {
-    int name_length = static_cast<int>(strlen(name));
-    *buffer =
-        reinterpret_cast<char*>(calloc(path_separator + name_length + 2, 1));
-    *buffer[0] = '\0';
-    strncat(*buffer, exec_path, path_separator + 1);
-    strncat(*buffer, name, name_length);
-  } else {
-    *buffer = strdup(name);
-  }
-  return *buffer;
-}
-
 }  // namespace
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
 
 void InitializeExternalStartupData(const char* directory_path) {
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
   char* natives;
   char* snapshot;
   LoadFromFiles(RelativePath(&natives, directory_path, "natives_blob.bin"),
                 RelativePath(&snapshot, directory_path, "snapshot_blob.bin"));
   free(natives);
   free(snapshot);
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 }
 
 
 void InitializeExternalStartupData(const char* natives_blob,
                                    const char* snapshot_blob) {
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
   LoadFromFiles(natives_blob, snapshot_blob);
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 }
 
 }  // namespace internal
 }  // namespace v8