Move OmahaQueryParams to a component and add a delegate interface.

components/omaha_query_params/omaha_query_params.h

+// 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.
+
+#ifndef COMPONENTS_OMAHA_QUERY_PARAMS_OMAHA_QUERY_PARAMS_H_
+#define COMPONENTS_OMAHA_QUERY_PARAMS_OMAHA_QUERY_PARAMS_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+
+// Generates a string of URL query parameters to be used when getting
+// component and extension updates. These parameters generally remain
+// fixed for a particular build. Embedders can use the delegate to
+// define different implementations. This should be used only in the
+// browser process.
+class OmahaQueryParams {
+ public:
+  enum ProdId {
+    CHROME = 0,
+    CRX,
+  };
+
+  // Generates a string of URL query parameters for Omaha. Includes the
+  // following fields: os, arch, prod, prodchannel, prodversion, lang.
+  static std::string Get(ProdId prod);
+
+  // Returns the value we use for the "prod=" parameter. Possible return values
+  // include "chrome", "chromecrx", "chromiumcrx", and "unknown".
+  static const char* GetProdIdString(ProdId prod);
+
+  // Returns the value we use for the "os=" parameter. Possible return values
+  // include: "mac", "win", "android", "cros", "linux", and "openbsd".
+  static const char* GetOS();
+
+  // Returns the value we use for the "arch=" parameter. Possible return values
+  // include: "x86", "x64", and "arm".
+  static const char* GetArch();
+
+  // Returns the value we use for the "nacl_arch" parameter. Note that this may
+  // be different from the "arch" parameter above (e.g. one may be 32-bit and
+  // the other 64-bit). Possible return values include: "x86-32", "x86-64",
+  // "arm", and "mips32".
+  static const char* GetNaclArch();
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(OmahaQueryParams);
+};
+
+// Embedders can specify an OmahaQueryParamsDelegate to provide additional
+// custom parameters. If not specified (Set is never called), no additional
+// parameters are added.
+class OmahaQueryParamsDelegate {
+ public:
+  OmahaQueryParamsDelegate();
+  virtual ~OmahaQueryParamsDelegate();
+
+  // Use this delegate.
+  static void Set(OmahaQueryParamsDelegate* delegate);
+
+  // Returns additional parameters, if any. If there are any parameters, the
+  // string should begin with a & character.
+  virtual std::string GetExtraParams() = 0;
+
+  DISALLOW_COPY_AND_ASSIGN(OmahaQueryParamsDelegate);
+};
+
+#endif  // COMPONENTS_OMAHA_QUERY_PARAMS_OMAHA_QUERY_PARAMS_H_