Hook up ProfileIOData's URLRequestContext to a NetworkService.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 2a6c4cb5e480edfd3a234224490b7a75f09266c8..61d4b565a85aad9a6d365e7873d72ea188204f94 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -53,6 +53,8 @@
 #include "chrome/browser/memory/chrome_memory_coordinator_delegate.h"
 #include "chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h"
 #include "chrome/browser/nacl_host/nacl_browser_delegate_impl.h"
+#include "chrome/browser/net/profile_network_context_service.h"
+#include "chrome/browser/net/profile_network_context_service_factory.h"
 #include "chrome/browser/net_benchmarking.h"
 #include "chrome/browser/notifications/platform_notification_service_impl.h"
 #include "chrome/browser/page_load_metrics/experiments/delay_navigation_throttle.h"
@@ -2686,6 +2688,20 @@ void ChromeContentBrowserClient::GetURLRequestAutoMountHandlers(
   return g_browser_process->rappor_service();
 }
 
+content::mojom::NetworkContextPtr
+ChromeContentBrowserClient::CreateNetworkContext(
+    content::BrowserContext* context,
+    bool in_memory,
+    const base::FilePath& relative_partition_path) {
+  if (relative_partition_path.empty()) {
+    return ProfileNetworkContextServiceFactory::GetForContext(context)
+        ->CreateMainNetworkContext();
+  }
+  // TODO(mmenke):  Implement this.

[Randy Smith (Not in Mondays), 2017/07/20 17:38:34]

nit, suggestion: Enhance TODO to indicate what's missing from this path.

[Randy Smith (Not in Mondays), 2017/07/20 17:38:34]

Confirming that this TODO is basically parallel to the TODO that used to be in
StoragePartitionImpl::Create() around filling in context_param?

[mmenke, 2017/07/20 18:31:30]

Not quite analogous - I'm not sure it will even make sense to populate them in
content/ (As opposed to having individual embedders populate them), though not
at all certain of that.

[mmenke, 2017/07/20 18:31:30]

Done.  Left this pretty general ("Implement this once
ProfileNetworkContextServiceFactory can create a fully functional NetworkContext
for Apps when the network service is disabled.").  We could implement it before
then, but I'm not sure how much benefit there would be.

+  return ContentBrowserClient::CreateNetworkContext(context, in_memory,
+                                                    relative_partition_path);
+}
+
 void ChromeContentBrowserClient::GetAdditionalFileSystemBackends(
     content::BrowserContext* browser_context,
     const base::FilePath& storage_partition_path,