Upstream Chrome on iOS source code [4/11].

ios/chrome/browser/ui/contextual_search/protos/client_discourse_context.proto

+// 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.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+
+package discourse_context;
+
+message ClientDiscourseContext {
+  // Displays that have been shown to the user.
+  repeated Display display = 4;
+}
+
+message Display {
+  // A media item in the display, e.g. a webpage.
+  optional Media media = 9;
+  // URI describing this content, e.g. the URL of the webpage.
+  optional string uri = 10;
+  // User-selected text and surrounding content.
+  optional Selection selection = 13;
+}
+
+message Selection {
+  // Character encoding is specified in media.mime_type.
+  optional string content = 1;
+  // Character offsets (inclusive, non-inclusive) into content of the selected
+  // text.
+  optional int32 start = 2;
+  optional int32 end = 3;
+}
+
+message Media {
+  // The MIME type of the media item.
+  optional string mime_type = 3;
+}