AU: Lower HTTP timeout on official builds.

We grew the timeout from 90s to 3 min a while back to give developers
more time to let the dev server build images. Unfortunately, this
means official builds take longer to time out when they have a bad
HTTP connection. This CL restores the 90s timeout on official builds.

BUG=chromium-os:13793
TEST=on device testing

Change-Id: Ia7a6474331770b3db3425147921d24077452c097

Review URL: http://codereview.chromium.org/6804001
diff --git a/libcurl_http_fetcher.cc b/libcurl_http_fetcher.cc
index e46bf8e..af7e845 100644
--- a/libcurl_http_fetcher.cc
+++ b/libcurl_http_fetcher.cc
@@ -116,7 +116,11 @@
   // If the connection drops under 10 bytes/sec for 3 minutes, reconnect.
   CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_LOW_SPEED_LIMIT, 10),
            CURLE_OK);
-  CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_LOW_SPEED_TIME, 3 * 60),
+  // Use a smaller timeout on official builds, larger for dev. Dev users
+  // want a longer timeout b/c they may be waiting on the dev server to
+  // build an image.
+  const int kTimeout = IsOfficialBuild() ? 90 : 3 * 60;
+  CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_LOW_SPEED_TIME, kTimeout),
            CURLE_OK);
 
   // By default, libcurl doesn't follow redirections. Allow up to