Support building selected C/C++ files in msvs-ninja

pylib/gyp/win_tool.py

Index: pylib/gyp/win_tool.py
diff --git a/pylib/gyp/win_tool.py b/pylib/gyp/win_tool.py
index 22dea0dbff133039da0b837dbcd2c32fe8f391e0..7e2d968ed575e6bfb1cad0fb7e69aaffda6cbbd7 100755
--- a/pylib/gyp/win_tool.py
+++ b/pylib/gyp/win_tool.py
@@ -299,5 +299,16 @@ class WinTool(object):
     dir = dir[0] if dir else None
     return subprocess.call(args, shell=True, env=env, cwd=dir)
 
+  def ExecClCompile(self, project_dir, selected_files):
+    """Executed by msvs-ninja projects when the 'ClCompile' target is used to
+    build selected C/C++ files."""
+    project_dir = os.path.relpath(project_dir, BASE_DIR)
+    selected_files = selected_files.split(';')
+    ninja_targets = [os.path.join(project_dir, filename) + '^^'
+        for filename in selected_files]
+    cmd = ['ninja.exe']
+    cmd.extend(ninja_targets)
+    return subprocess.call(cmd, shell=True, cwd=BASE_DIR)
+
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))