Add a NetworkQualityEstimator to TestURLRequestContext.

net/url_request/url_request_test_util.cc

Index: net/url_request/url_request_test_util.cc
diff --git a/net/url_request/url_request_test_util.cc b/net/url_request/url_request_test_util.cc
index cc56ef300f17749a68d8e34a8ad93fb986611921..336514659c59a64686171307d63c9cfb030992b9 100644
--- a/net/url_request/url_request_test_util.cc
+++ b/net/url_request/url_request_test_util.cc
@@ -4,6 +4,8 @@
 
 #include "net/url_request/url_request_test_util.h"
 
+#include <map>
+#include <string>
 #include <utility>
 
 #include "base/compiler_specific.h"
@@ -24,6 +26,7 @@
 #include "net/http/http_response_headers.h"
 #include "net/http/http_server_properties_impl.h"
 #include "net/http/transport_security_state.h"
+#include "net/nqe/external_estimate_provider.h"
 #include "net/proxy/proxy_retry_info.h"
 #include "net/ssl/channel_id_service.h"
 #include "net/ssl/default_channel_id_store.h"
@@ -57,7 +60,9 @@ const int kStageDestruction = 1 << 10;
 TestURLRequestContext::TestURLRequestContext() : TestURLRequestContext(false) {}
 
 TestURLRequestContext::TestURLRequestContext(bool delay_initialization)
-    : context_storage_(this) {
+    : network_quality_estimator_(std::unique_ptr<ExternalEstimateProvider>(),
+                                 std::map<std::string, std::string>()),
+      context_storage_(this) {
   if (!delay_initialization)
     Init();
 }
@@ -112,6 +117,10 @@ void TestURLRequestContext::Init() {
         new DefaultChannelIDStore(nullptr),
         base::WorkerPool::GetTaskRunner(true)));
   }
+
+  if (!network_quality_estimator())
+    set_network_quality_estimator(&network_quality_estimator_);
+
   if (http_transaction_factory()) {
     // Make sure we haven't been passed an object we're not going to use.
     EXPECT_FALSE(client_socket_factory_);
@@ -133,6 +142,8 @@ void TestURLRequestContext::Init() {
     params.http_server_properties = http_server_properties();
     params.net_log = net_log();
     params.channel_id_service = channel_id_service();
+    params.socket_performance_watcher_factory =

[tbansal1, 2016/11/14 20:26:01]

Currently, the problem is that in some tests, |params| does not have NQE set.
With this fix, NQE will be set for params, but in some tests, |params| will have
a different NQE than the context.

Would a better solution be for NQE tests to override the |params| too?
Similar to:
https://cs.chromium.org/chromium/src/net/nqe/network_quality_estimator_unitte...
If yes, I can do that for all NQE tests since I have already done it for one
other test. wdyt?

[mmenke, 2016/11/14 20:29:52]

A better solution instead of this CL, or in addition to this CL?

The goal of this CL is to make TestURLRequestContext better reflect the main
URLRequestContext in production code, and that includes the NQE.  Even if most
tests using the TestURLRequestContext don't explicitly check the NQE, this will
let them exercise its code, and make sure it doesn't crash or DCHECK under a
greater variety of circumstances than it makes sense to have explicit NQE tests
for.

[tbansal1, 2016/11/14 20:39:27]

"In addition to". OK, I will do that after this CL is submitted.
Got it.

+        network_quality_estimator()->GetSocketPerformanceWatcherFactory();
     context_storage_.set_http_network_session(
         base::MakeUnique<HttpNetworkSession>(params));
     context_storage_.set_http_transaction_factory(base::MakeUnique<HttpCache>(