Mojo content handler shebang support

mojo/common/data_pipe_utils.h

Index: mojo/common/data_pipe_utils.h
diff --git a/mojo/common/data_pipe_utils.h b/mojo/common/data_pipe_utils.h
index dc2197b6e07fd14a7d1f08ec4da610e852367a5c..5952d9a03ba510dbf84a4f45c0f46c5c8e50d6d6 100644
--- a/mojo/common/data_pipe_utils.h
+++ b/mojo/common/data_pipe_utils.h
@@ -35,6 +35,23 @@ bool MOJO_COMMON_EXPORT BlockingCopyToString(
     ScopedDataPipeConsumerHandle source,
     std::string* contents);
 
+// 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 MOJO_COMMON_EXPORT 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 MOJO_COMMON_EXPORT BlockingPeekNBytes(
+    DataPipeConsumerHandle source,
+    std::string* bytes,
+    size_t bytes_length,
+    MojoDeadline timeout);
+
 }  // namespace common
 }  // namespace mojo