Make FileStat have millisecond precisions, for linux, mac and android.

runtime/bin/file_linux.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"
 #if defined(TARGET_OS_LINUX)
 
 #include "bin/file.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 274 matching lines @@
 
 int64_t File::LengthFromPath(const char* name) {
   struct stat64 st;
   if (NO_RETRY_EXPECTED(stat64(name, &st)) == 0) {
     return st.st_size;
   }
   return -1;
 }
 
 
+static int64_t TimespecToMilliseconds(const struct timespec& t) {
+  return static_cast<int64_t>(t.tv_sec) * 1000L +
+      static_cast<int64_t>(t.tv_nsec) / 1000000L;
+}
+
+
 void File::Stat(const char* name, int64_t* data) {
   struct stat64 st;
   if (NO_RETRY_EXPECTED(stat64(name, &st)) == 0) {
     if (S_ISREG(st.st_mode)) {
       data[kType] = kIsFile;
     } else if (S_ISDIR(st.st_mode)) {
       data[kType] = kIsDirectory;
     } else if (S_ISLNK(st.st_mode)) {
       data[kType] = kIsLink;
     } else {
       data[kType] = kDoesNotExist;
     }
-    data[kCreatedTime] = st.st_ctime;
-    data[kModifiedTime] = st.st_mtime;
-    data[kAccessedTime] = st.st_atime;
+    data[kCreatedTime] = TimespecToMilliseconds(st.st_ctim);
+    data[kModifiedTime] = TimespecToMilliseconds(st.st_mtim);
+    data[kAccessedTime] = TimespecToMilliseconds(st.st_atim);
     data[kMode] = st.st_mode;
     data[kSize] = st.st_size;
   } else {
     data[kType] = kDoesNotExist;
   }
 }
 
 
 time_t File::LastModified(const char* name) {
   struct stat64 st;
@@ skipping 95 matching lines @@
   return (file_1_info.st_ino == file_2_info.st_ino &&
           file_1_info.st_dev == file_2_info.st_dev) ?
       File::kIdentical :
       File::kDifferent;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)