Add build and patch to Chrome-Proxy header

chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc

Index: chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
diff --git a/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc b/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
index 26be2de2cd7dc939dba07a2f3d4b57d189009c0c..bbdb1df8db142c37f71e26861044d77a0aec9e17 100644
--- a/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
+++ b/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
@@ -54,13 +54,35 @@ void DataReductionProxyChromeSettings::RegisterSyntheticFieldTrial(
 }
 
 // static
-std::string DataReductionProxyChromeSettings::GetBuildAndPatchNumber() {
+std::string DataReductionProxyChromeSettings::GetBuildNumber() {
   chrome::VersionInfo version_info;
+  return GetBuildNumberFromString(version_info.Version());
+}
+
+// static
+std::string DataReductionProxyChromeSettings::GetBuildNumberFromString(

[bengr, 2014/09/03 22:28:38]

How often is this called? If once, I'm ok with the structure. If it's on every
request, then to avoid copies, do bool GetBuildNumberFromString(std::string*
build_number);

[megjablon, 2014/09/04 00:41:06]

Only once

+    std::string version) {
+  std::vector<std::string> version_parts;
+  base::SplitString(version, '.', &version_parts);
+  if (version_parts.size() != 4)
+    return std::string();
+  return version_parts[2];
+}
+
+// static
+std::string DataReductionProxyChromeSettings::GetPatchNumber() {

[bengr, 2014/09/03 22:28:39]

To avoid repetition, I'd have one function called void
GetChromiumVersionComponent(const std::string& version, size_t component_index);

Then have GetBuildNumberFromString call
GetChromiumVersionComponent(version_info.Version(), 2) and have
GetPatchNumberFromString call
GetChromiumVersionComponent(version_info.Version(), 3)

+  chrome::VersionInfo version_info;
+  return GetPatchNumberFromString(version_info.Version());
+}
+
+// static
+std::string DataReductionProxyChromeSettings::GetPatchNumberFromString(
+    std::string version) {
   std::vector<std::string> version_parts;
-  base::SplitString(version_info.Version(), '.', &version_parts);
+  base::SplitString(version, '.', &version_parts);
   if (version_parts.size() != 4)
-    return "";
-  return version_parts[2] + version_parts[3];
+    return std::string();
+  return version_parts[3];
 }
 
 // static