Add a mojo channel for frame messages.

content/browser/frame_host/input/legacy_ipc_frame_input_handler.h

Index: content/browser/frame_host/input/legacy_ipc_frame_input_handler.h
diff --git a/content/browser/frame_host/input/legacy_ipc_frame_input_handler.h b/content/browser/frame_host/input/legacy_ipc_frame_input_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..46436e0d470a8030fede98b807c098df1b6d9a6b
--- /dev/null
+++ b/content/browser/frame_host/input/legacy_ipc_frame_input_handler.h
@@ -0,0 +1,62 @@
+// Copyright 2017 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.
+
+#ifndef CONTENT_BROWSER_FRAME_HOST_INPUT_LEGACY_IPC_FRAME_INPUT_HANDLER_H_
+#define CONTENT_BROWSER_FRAME_HOST_INPUT_LEGACY_IPC_FRAME_INPUT_HANDLER_H_
+
+#include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/renderer_host/input/input_router_impl.h"
+#include "content/common/input/input_handler.mojom.h"
+
+namespace content {
+
+// An instance of a mojom::FrameInputHandler based on chrome IPC.
+// This class is a temporary class to allow the input messages to
+// remain as Chrome IPC messages but progressively work at moving
+// them to mojo.
+class CONTENT_EXPORT LegacyIPCFrameInputHandler
+    : public mojom::FrameInputHandler {
+ public:
+  LegacyIPCFrameInputHandler(RenderFrameHostImpl* frame_host, int routing_id);
+  ~LegacyIPCFrameInputHandler() override;
+
+  void SetCompositionFromExistingText(
+      int32_t start,
+      int32_t end,
+      const std::vector<ui::CompositionUnderline>& underlines) override;
+  void ExtendSelectionAndDelete(int32_t before, int32_t after) override;
+  void DeleteSurroundingText(int32_t before, int32_t after) override;
+  void DeleteSurroundingTextInCodePoints(int32_t before,
+                                         int32_t after) override;
+  void SetEditableSelectionOffsets(int32_t start, int32_t end) override;
+  void ExecuteEditCommand(const std::string& command,
+                          const base::Optional<base::string16>& value) override;
+  void Undo() override;
+  void Redo() override;
+  void Cut() override;
+  void Copy() override;
+  void CopyToFindPboard() override;
+  void Paste() override;
+  void PasteAndMatchStyle() override;
+  void Replace(const base::string16& word) override;
+  void ReplaceMisspelling(const base::string16& word) override;
+  void Delete() override;
+  void SelectAll() override;
+  void CollapseSelection() override;
+  void SelectRange(const gfx::Point& base, const gfx::Point& extent) override;
+  void AdjustSelectionByCharacterOffset(int32_t start, int32_t end) override;
+  void MoveRangeSelectionExtent(const gfx::Point& extent) override;
+
+ private:
+  void SendInput(std::unique_ptr<IPC::Message> message);
+
+  RenderFrameHostImpl* frame_host_;
+  int routing_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(LegacyIPCFrameInputHandler);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_FRAME_HOST_INPUT_LEGACY_IPC_FRAME_INPUT_HANDLER_H_