Mojo content handler shebang support

mojo/shell/data_pipe_peek.h

+// Copyright 2014 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 <string>
+
+#include "mojo/public/cpp/system/core.h"
+
+namespace mojo {
+namespace shell {
+
+// The Peek functions are only intended to be used by the
+// DyanmicApplicationLoader class for discovering the type of a
+// URL response. They are a stopgap to be replaced by real support
+// in the DataPipe classes.
+
+// Return true and the first newline terminated line from source. Return false
+// if more than max_line_length bytes are scanned without seeing a newline, or
+// if the timeout is exceeded.
+bool BlockingPeekLine(
+    DataPipeConsumerHandle source,
+    std::string* line,
+    size_t max_line_length,
+    MojoDeadline timeout);
+
+// Return true and the first bytes_length bytes from source. Return false
+// if the timeout is exceeded.
+bool BlockingPeekNBytes(
+    DataPipeConsumerHandle source,
+    std::string* bytes,
+    size_t bytes_length,
+    MojoDeadline timeout);
+
+} // namespace shell
+} // namespace mojo