Add FrameHost mojo service

content/browser/host_zoom_level_impl.h

+// Copyright 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 CONTENT_BROWSER_HOST_ZOOM_LEVEL_IMPL_H_
+#define CONTENT_BROWSER_HOST_ZOOM_LEVEL_IMPL_H_
+
+#include "content/common/host_zoom_level.mojom.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+
+namespace content {
+
+class BrowserContext;
+
+class HostZoomLevelImpl : public mojom::HostZoomLevel {
+ public:
+  HostZoomLevelImpl(BrowserContext* context,
+                    int render_process_id,

[jam, 2016/05/16 18:28:32]

these two parameters are redundant, since one can get to BrowserContext from
render_process_id.

Can you just pass in render_process_id, and then when you need the
BHostZoomMapImpl you can do:
RenderProcessHost::FromID(render_process_id)->GetStoragePartition()->GetHostZoomMap()

[scottmg, 2016/05/16 22:54:56]

Done.

+                    mojom::HostZoomLevelRequest request);
+  ~HostZoomLevelImpl() override;
+
+  static void Create(BrowserContext* context,
+                     int render_process_id,
+                     mojom::HostZoomLevelRequest request);
+
+ private:
+  // mojom::HostZoomLevel:
+  void GetZoomLevel(const GURL& url,
+                    int32_t render_view_id,
+                    const GetZoomLevelCallback& callback) override;
+
+  mojo::Binding<mojom::HostZoomLevel> binding_;
+  BrowserContext* context_;
+  int render_process_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(HostZoomLevelImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_HOST_ZOOM_LEVEL_IMPL_H_