Add support for variations controlled overriding UI strings to the variations service.

chrome/browser/metrics/variations/generated_resources_map_lookup.cc

Index: chrome/browser/metrics/variations/generated_resources_map_lookup.cc
diff --git a/chrome/browser/metrics/variations/generated_resources_map_lookup.cc b/chrome/browser/metrics/variations/generated_resources_map_lookup.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7f96b7e3969cb257745b6714661ddeb03d83aa34
--- /dev/null
+++ b/chrome/browser/metrics/variations/generated_resources_map_lookup.cc
@@ -0,0 +1,20 @@
+// 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.
+
+#include "chrome/browser/metrics/variations/generated_resources_map.h"
+
+#include <algorithm>
+
+namespace chrome_variations {
+
+int GetResourceIndex(uint32_t hash) {
+  const uint32_t* kEnd = kResourceHashes + kNumResources;
+  const uint32_t* kElement = std::lower_bound(kResourceHashes, kEnd, hash);

[Alexei Svitkine (slow), 2014/07/03 17:54:40]

Nit: kNaming convention is only used for compile-time constants. Since this is a
run-time constant, don't use it here.

[jwd, 2014/07/07 15:52:20]

Done.

+
+  if (kElement == kEnd || *kElement != hash)

[Alexei Svitkine (slow), 2014/07/03 17:54:40]

Is the first cond needed or will the second catch both of them? If so, just keep
the second cond but add a comment explaining it.

[jwd, 2014/07/07 15:52:20]

If element == kEnd, then it would be dereferencing memory beyond the bound of
the array.

+    return -1;
+  return  kResourceIndices[kElement - kResourceHashes];

[Alexei Svitkine (slow), 2014/07/03 17:54:40]

Nit: Remove extra space after return.

[jwd, 2014/07/07 15:52:20]

Done.

+}
+
+}  // namespace chrome_variations