Regenerate .mojo file if any dependent .dart sources change

mojo/dart/embedder/snapshotter/main.cc

 // 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 <iostream>
 
 #include "base/at_exit.h"
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 63 matching lines @@
 }
 
 void WriteDepfile(base::FilePath path,
                   const std::string& build_output,
                   const std::set<std::string>& deps) {
   base::FilePath current_directory;
   CHECK(base::GetCurrentDirectory(&current_directory));
   std::string output = build_output + ":";
   for (const auto& i : deps) {
     output += " ";
-    output += current_directory.Append(i).MaybeAsASCII();
+    base::FilePath file = base::FilePath(i);
+    if (!file.IsAbsolute()) {
+      file = current_directory.Append(i);
+    }
+    base::FilePath resolved_file;
+    if (!ReadSymbolicLink(file, &resolved_file)) {
+      // Not a symbolic link.
+      resolved_file = file;
+    }
+    output += resolved_file.MaybeAsASCII();
   }
   const char* data = output.c_str();
   const intptr_t data_length = output.size();
   CHECK_EQ(base::WriteFile(path, data, data_length), data_length);
 }
 
 int main(int argc, const char* argv[]) {
   base::AtExitManager exit_manager;
   base::EnableTerminationOnHeapCorruption();
   base::CommandLine::Init(argc, argv);
@@ skipping 47 matching lines @@
     CHECK(command_line.HasSwitch(kBuildOutput)) <<
         "Need --build-output with --depfile";
     // Write depfile.
     WriteDepfile(command_line.GetSwitchValuePath(kDepfile),
                  command_line.GetSwitchValueASCII(kBuildOutput),
                  library_provider->deps());
   }
 
   return 0;
 }