Add a Physical Web omnibox autocomplete provider

components/omnibox/browser/physical_web_provider.h

+// Copyright (c) 2016 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_OMNIBOX_BROWSER_PHYSICAL_WEB_PROVIDER_H_
+#define COMPONENTS_OMNIBOX_BROWSER_PHYSICAL_WEB_PROVIDER_H_
+
+#include "components/omnibox/browser/autocomplete_input.h"
+#include "components/omnibox/browser/autocomplete_provider.h"
+
+class AutocompleteProviderClient;
+
+namespace base {
+class ListValue;
+}
+
+class PhysicalWebProvider : public AutocompleteProvider {
+public:
+  static PhysicalWebProvider* Create(AutocompleteProviderClient* client);
+
+  // AutocompleteProvider:
+  void Start(const AutocompleteInput& input, bool minimal_changes) override;
+  void Stop(bool clear_cached_results, bool due_to_user_inactivity) override;
+
+private:
+  PhysicalWebProvider(AutocompleteProviderClient* client);
+  ~PhysicalWebProvider() override;
+
+  // Adds a separate match item to |matches_| for each nearby URL in
+  // |metadata_list|, up to the maximum number of matches allowed. If the total
+  // number of nearby URLs exceeds this limit, one match is used for an overflow
+  // item.
+  void ConstructMatches(base::ListValue* metadata_list);
+
+  // Adds an overflow match item to |matches_| with a relevance score equal to
+  // |relevance| and a label indicating there are |additional_url_count| more
+  // nearby URLs. Selecting the overflow item navigates to the Physical Web
+  // WebUI, which displays the full list of nearby URLs.
+  void AppendOverflowItem(int additional_url_count, int relevance);
+
+  AutocompleteProviderClient* client_;
+};
+
+#endif  // COMPONENTS_OMNIBOX_BROWSER_PHYSICAL_WEB_PROVIDER_H_