Added chrome switch that lets tests override URL path, moved GAIA auth extension from CrOS

chrome/common/net/gaia/gaia_urls.cc

Index: chrome/common/net/gaia/gaia_urls.cc
diff --git a/chrome/common/net/gaia/gaia_urls.cc b/chrome/common/net/gaia/gaia_urls.cc
index a4217d11fae047d0d5ac1c70a78fad9aabdc67b0..7051dacac0b0642233e285b765eb237d7c5d3438 100644
--- a/chrome/common/net/gaia/gaia_urls.cc
+++ b/chrome/common/net/gaia/gaia_urls.cc
@@ -63,6 +63,16 @@ GaiaUrls::GaiaUrls() {
 
   captcha_url_prefix_ = "http://" + host_base + kCaptchaUrlPrefixSuffix;
   gaia_origin_url_ = "https://" + host_base;
+  if (command_line->HasSwitch(switches::kGaiaUrlPath)) {
+    std::string path = command_line->GetSwitchValueASCII(switches::kGaiaUrlPath);
+    if (!path.empty()) {
+      if (path[0] != '/')
+        gaia_origin_url_.append("/");
+
+      gaia_origin_url_.append(path);
+    }
+  }
+
   client_login_url_ = gaia_origin_url_ + kClientLoginUrlSuffix;
   service_login_url_ = gaia_origin_url_ + kServiceLoginUrlSuffix;
   issue_auth_token_url_ = gaia_origin_url_ + kIssueAuthTokenUrlSuffix;