[Contextual Search] Add Mojo-enabled API component.

components/contextual_search/renderer/contextual_search_wrapper.h

+// Copyright 2015 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 COMPONENTS_CONTEXTUAL_SEARCH_RENDERER_CONTEXTUAL_SEARCH_WRAPPER_H_
+#define COMPONENTS_CONTEXTUAL_SEARCH_RENDERER_CONTEXTUAL_SEARCH_WRAPPER_H_
+
+#include "base/basictypes.h"
+#include "components/contextual_search/common/contextual_search_js_api_service.mojom.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_frame_observer.h"
+#include "gin/handle.h"
+#include "gin/wrappable.h"
+
+namespace blink {
+class WebFrame;
+}
+
+namespace gin {
+class Arguments;
+}
+
+namespace contextual_search {
+
+// Wrapper for injecting Contextual Search JavaScript
+// into a WebFrame.
+class ContextualSearchWrapper : public gin::Wrappable<ContextualSearchWrapper>,
+                                public content::RenderFrameObserver {
+ public:
+  // Installs Contextual Search JavaScript.
+  static void Install(content::RenderFrame* render_frame);
+
+  // RenderFrameObserver implementation.
+  void OnDestruct() override;
+
+  // Required by gin::Wrappable.
+  static gin::WrapperInfo kWrapperInfo;
+
+ private:
+  // Instantiate by calling Install.
+  explicit ContextualSearchWrapper(content::RenderFrame* render_frame);
+  ~ContextualSearchWrapper() override;
+
+  // gin::Wrappable.
+  gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
+      v8::Isolate* isolate) final;
+
+  // Called by JavaScript to set the caption , and indicate whether
+  // the caption provides an answer (e.g. an actual definition), rather than
+  // just general notification of what kind of answer may be available.
+  void SetCaption(const std::string& caption, bool does_answer);
+
+  // Helper function to ensure that this class has connected to the API service.
+  // Returns false if cannot connect.
+  bool EnsureServiceConnected();
+
+  // The service to notify when API calls are made.
+  ContextualSearchJsApiServicePtr contextual_search_js_api_service_;
+
+  DISALLOW_COPY_AND_ASSIGN(ContextualSearchWrapper);
+};
+
+}  // namespace contextual_search
+
+#endif  // COMPONENTS_CONTEXTUAL_SEARCH_RENDERER_CONTEXTUAL_SEARCH_WRAPPER_H_