Make ResourceHandler::OnWillRead able to complete asynchronously.

content/browser/loader/mojo_async_resource_handler_unittest.cc

Index: content/browser/loader/mojo_async_resource_handler_unittest.cc
diff --git a/content/browser/loader/mojo_async_resource_handler_unittest.cc b/content/browser/loader/mojo_async_resource_handler_unittest.cc
index 96515e0b6d3a3046fa1e1bab73e78ee3e483d497..04b5fa256521305cca1e201e8ce6dff18e6a250f 100644
--- a/content/browser/loader/mojo_async_resource_handler_unittest.cc
+++ b/content/browser/loader/mojo_async_resource_handler_unittest.cc
@@ -544,8 +544,7 @@ TEST_F(MojoAsyncResourceHandlerTest, OnWillReadWithInsufficientResource) {
   ASSERT_TRUE(CallOnWillStartAndOnResponseStarted());
 
   ASSERT_EQ(MockResourceLoader::Status::CANCELED, mock_loader_->OnWillRead());
-  // TODO(mmenke): Make this fail with net::ERR_INSUFFICIENT_RESOURCES.
-  EXPECT_EQ(net::ERR_ABORTED, mock_loader_->error_code());
+  EXPECT_EQ(net::ERR_INSUFFICIENT_RESOURCES, mock_loader_->error_code());
   EXPECT_EQ(1, rdh_.num_in_flight_requests_for_testing());
   handler_ = nullptr;
   EXPECT_EQ(0, rdh_.num_in_flight_requests_for_testing());