Fix Cronet load flag initialization

Load flags were being read from the CronetURLRequestContextAdapter
on the main thread, which could potentially happen before they were
initialized on the network thread if a UrlRequest is created immediately
after the CronetEngine. Now they are read at request start time on the
network thread, which must be after context initialization.

BUG=743232

Change-Id: I3f9c5cd1cde906555c5ba68b4a45a9a3ee71b014
Reviewed-on: https://chromium-review.googlesource.com/574827Reviewed-by: Paul Jensen <pauljensen@chromium.org>
Commit-Queue: Miriam Gershenson <mgersh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487227}

components/cronet/android/cronet_url_request_adapter.cc

@@ -91,7 +91,7 @@ CronetURLRequestAdapter::CronetURLRequestAdapter(
       initial_url_(url),
       initial_priority_(priority),
       initial_method_("GET"),
-      load_flags_(context->default_load_flags()),
+      load_flags_(net::LOAD_NORMAL),
       enable_metrics_(jenable_metrics == JNI_TRUE),
       metrics_reported_(false) {
   DCHECK(!context_->IsOnNetworkThread());
@@ -304,7 +304,7 @@ void CronetURLRequestAdapter::StartOnNetworkThread() {
           << " priority: " << RequestPriorityToString(initial_priority_);
   url_request_ = context_->GetURLRequestContext()->CreateRequest(
       initial_url_, net::DEFAULT_PRIORITY, this);
-  url_request_->SetLoadFlags(load_flags_);
+  url_request_->SetLoadFlags(load_flags_ | context_->default_load_flags());
   url_request_->set_method(initial_method_);
   url_request_->SetExtraRequestHeaders(initial_request_headers_);
   url_request_->SetPriority(initial_priority_);

components/cronet/android/cronet_url_request_context_adapter.cc

@@ -962,6 +962,11 @@ void CronetURLRequestContextAdapter::GetCertVerifierDataOnNetworkThread() {
       base::android::ConvertUTF8ToJavaString(env, encoded_data).obj());
 }
 
+int CronetURLRequestContextAdapter::default_load_flags() const {
+  DCHECK(is_context_initialized_);
+  return default_load_flags_;
+}
+
 base::Thread* CronetURLRequestContextAdapter::GetFileThread() {
   DCHECK(GetNetworkTaskRunner()->BelongsToCurrentThread());
   if (!file_thread_) {

components/cronet/android/cronet_url_request_context_adapter.h

@@ -108,7 +108,7 @@ class CronetURLRequestContextAdapter
                            const base::android::JavaParamRef<jobject>& jcaller);
 
   // Default net::LOAD flags used to create requests.
-  int default_load_flags() const { return default_load_flags_; }
+  int default_load_flags() const;
 
   // Called on init Java thread to initialize URLRequestContext.
   void InitRequestContextOnInitThread();

components/cronet/android/test/javatests/src/org/chromium/net/CronetUrlRequestContextTest.java

@@ -544,11 +544,15 @@ public class CronetUrlRequestContextTest extends CronetTestBase {
 
     private CronetEngine createCronetEngineWithCache(int cacheType) {
         CronetEngine.Builder builder = new CronetEngine.Builder(getContext());
-        if (cacheType == CronetEngine.Builder.HTTP_CACHE_DISK) {
+        if (cacheType == CronetEngine.Builder.HTTP_CACHE_DISK
+                || cacheType == CronetEngine.Builder.HTTP_CACHE_DISK_NO_HTTP) {
             builder.setStoragePath(getTestStorage(getContext()));
         }
         builder.enableHttpCache(cacheType, 100 * 1024);
-        assertTrue(NativeTestServer.startNativeTestServer(getContext()));
+        // Don't check the return value here, because startNativeTestServer() returns false when the
+        // NativeTestServer is already running and this method needs to be called twice without
+        // shutting down the NativeTestServer in between.
+        NativeTestServer.startNativeTestServer(getContext());
         return builder.build();
     }
 
@@ -961,13 +965,20 @@ public class CronetUrlRequestContextTest extends CronetTestBase {
     @Feature({"Cronet"})
     @OnlyRunNativeCronet
     public void testEnableHttpCacheDiskNoHttp() throws Exception {
-        // TODO(pauljensen): This should be testing HTTP_CACHE_DISK_NO_HTTP.
         CronetEngine cronetEngine =
-                createCronetEngineWithCache(CronetEngine.Builder.HTTP_CACHE_DISABLED);
+                createCronetEngineWithCache(CronetEngine.Builder.HTTP_CACHE_DISK_NO_HTTP);
         String url = NativeTestServer.getFileURL("/cacheable.txt");
         checkRequestCaching(cronetEngine, url, false);
         checkRequestCaching(cronetEngine, url, false);
         checkRequestCaching(cronetEngine, url, false);
+
+        // Make a new CronetEngine and try again to make sure the response didn't get cached on the
+        // first request. See https://crbug.com/743232.
+        cronetEngine.shutdown();
+        cronetEngine = createCronetEngineWithCache(CronetEngine.Builder.HTTP_CACHE_DISK_NO_HTTP);
+        checkRequestCaching(cronetEngine, url, false);
+        checkRequestCaching(cronetEngine, url, false);
+        checkRequestCaching(cronetEngine, url, false);
     }
 
     @SmallTest