[Cronet] Respect user agent string from config

components/cronet/android/java/src/org/chromium/net/ChromiumUrlRequestFactory.java

Index: components/cronet/android/java/src/org/chromium/net/ChromiumUrlRequestFactory.java
diff --git a/components/cronet/android/java/src/org/chromium/net/ChromiumUrlRequestFactory.java b/components/cronet/android/java/src/org/chromium/net/ChromiumUrlRequestFactory.java
index e5a224afe1a542441f272dbe2626ea4d3d9fc19e..a1b02818c8b921fb26c8b1b78d3d76b2a2e36556 100644
--- a/components/cronet/android/java/src/org/chromium/net/ChromiumUrlRequestFactory.java
+++ b/components/cronet/android/java/src/org/chromium/net/ChromiumUrlRequestFactory.java
@@ -23,8 +23,14 @@ public class ChromiumUrlRequestFactory extends HttpUrlRequestFactory {
     public ChromiumUrlRequestFactory(
             Context context, UrlRequestContextConfig config) {
         if (isEnabled()) {
-            mRequestContext =
-                    new ChromiumUrlRequestContext(context, UserAgent.from(context), config);
+            String userAgent = config.userAgent();
+            if (!userAgent.isEmpty()) {

[mef, 2015/03/16 15:39:55]

Suggest changing to: 

if (userAgent.isEmpty())
  userAgent = UserAgent.from(context);

and removing else clause.

[xunjieli, 2015/03/16 15:45:56]

Done.

+                mRequestContext = new ChromiumUrlRequestContext(context,
+                        userAgent, config);
+            } else {
+                mRequestContext = new ChromiumUrlRequestContext(context,
+                        UserAgent.from(context), config);
+            }
         }
     }