Make Cronet's upload test server to serve files

components/cronet/android/test/src/org/chromium/cronet_test_apk/UploadTestServer.java

Index: components/cronet/android/test/src/org/chromium/cronet_test_apk/UploadTestServer.java
diff --git a/components/cronet/android/test/src/org/chromium/cronet_test_apk/UploadTestServer.java b/components/cronet/android/test/src/org/chromium/cronet_test_apk/UploadTestServer.java
index 85301b015d9861cd4ec0febe853aebd1b3c63734..f03beafa5eab2d4f26cf5f32ec0ee69e0f314049 100644
--- a/components/cronet/android/test/src/org/chromium/cronet_test_apk/UploadTestServer.java
+++ b/components/cronet/android/test/src/org/chromium/cronet_test_apk/UploadTestServer.java
@@ -40,6 +40,10 @@ public final class UploadTestServer {
         return nativeGetRedirectToEchoBody();
     }
 
+    public static String getFileURL(String filePath) {
+        return nativeGetFileURL(filePath);
+    }
+
     private static native boolean nativeStartUploadTestServer();
     private static native void nativeShutdownUploadTestServer();
     private static native String nativeGetEchoBodyURL();
@@ -47,4 +51,5 @@ public final class UploadTestServer {
     private static native String nativeGetEchoAllHeadersURL();
     private static native String nativeGetEchoMethodURL();
     private static native String nativeGetRedirectToEchoBody();
+    private static native String nativeGetFileURL(String filePath);
 }