Address test network issues

[ Merge of http://go/wvgerrit/22140 ]

There are occasional issues when trying to connect to
http://widevine-proxy.appspot.com/proxy . This changes introduces upto
3 retry attempts. The UAT server on appspot is being replaced by UAT on borg
and so it is not worth our while to debug these issues furthur.

b/30022298

Change-Id: I76c1421e93c7c14b5d2bcd7ad07119a705245922

libwvdrmengine/cdm/core/test/url_request.cpp

@@ -13,6 +13,7 @@ namespace wvcdm {
 
 namespace {
 
+const int kMaxConnectAttempts = 3;
 const int kReadBufferSize = 1024;
 const int kConnectTimeoutMs = 15000;
 const int kWriteTimeoutMs = 12000;
@@ -79,6 +80,7 @@ UrlRequest::UrlRequest(const std::string& url)
 UrlRequest::~UrlRequest() {}
 
 void UrlRequest::Reconnect() {
+  for(uint32_t i = 0; i < kMaxConnectAttempts && !is_connected_; ++i) {
     socket_.CloseSocket();
     if (socket_.Connect(kConnectTimeoutMs)) {
       is_connected_ = true;
@@ -87,6 +89,7 @@ void UrlRequest::Reconnect() {
            socket_.port());
     }
   }
+}
 
 bool UrlRequest::GetResponse(std::string* message) {
   std::string response;