Move CreateDefaultURLLoaderFactoryBundle to anonymous namespace.

After removing blink::Platform::CreateDefaultURLLoaderFactory method in
r783649, there are no more callers of CreateNetworkURLLoaderFactory and
CreateDefaultURLLoaderFactoryBundle _inside_ RendererBlinkPlatformImpl.
Therefore, this CL moves CreateNetworkURLLoaderFactory and
CreateDefaultURLLoaderFactoryBundle into an anonymous namespace in
render_frame_impl.cc, where their only remaining caller is.

This helps (slightly) in two ways:

1. It helps with encapsulation - after the CL, no headers expose an API
   for getting the origin-agnostic/process-wide factory via
   CreateDefaultURLLoaderFactoryBundle.

2. It highlights that the helpers are unrelated from
   RendererBlinkPlatformImpl - even before this CL they could have been
   |static| methods.

Bug: 1098938
Change-Id: I7a13c4d4fdfaaedda25acfa7f40404d307a2b537
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2276227Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Commit-Position: refs/heads/master@{#784838}

content/renderer/render_frame_impl.cc

@@ -1055,6 +1055,35 @@ void FillNavigationParamsOriginPolicy(
   }
 }
 
+// Asks RenderProcessHostImpl::CreateURLLoaderFactoryForRendererProcess in the
+// browser process for a URLLoaderFactory.
+//
+// AVOID: see the comment on CreateDefaultURLLoaderFactoryBundle below.
+mojo::PendingRemote<network::mojom::URLLoaderFactory>
+CreateDefaultURLLoaderFactory() {
+  RenderThreadImpl* render_thread = RenderThreadImpl::current();
+  DCHECK(render_thread);
+  mojo::PendingRemote<network::mojom::URLLoaderFactory> factory_remote;
+  ChildThread::Get()->BindHostReceiver(
+      factory_remote.InitWithNewPipeAndPassReceiver());
+  return factory_remote;
+}
+
+// Returns a non-null pointer to a URLLoaderFactory bundle that is not
+// associated with any specific origin, frame or worker.
+//
+// AVOID: prefer to use an origin/frame/worker-specific factory (e.g. via
+// content::RenderFrameImpl::FrameURLLoaderFactory::CreateURLLoader).  See
+// also https://crbug.com/1098938.
+//
+// It is invalid to call this in an incomplete env where
+// RenderThreadImpl::current() returns nullptr (e.g. in some tests).
+scoped_refptr<ChildURLLoaderFactoryBundle>
+CreateDefaultURLLoaderFactoryBundle() {
+  return base::MakeRefCounted<ChildURLLoaderFactoryBundle>(
+      base::BindOnce(&CreateDefaultURLLoaderFactory));
+}
+
 }  // namespace
 
 // This class uses existing WebNavigationBodyLoader to read the whole response
@@ -5739,16 +5768,15 @@ RenderFrameImpl::CreateLoaderFactoryBundle(
       base::MakeRefCounted<HostChildURLLoaderFactoryBundle>(
           GetTaskRunner(blink::TaskType::kInternalLoading));
 
-  // In some tests |render_thread| could be null.
-  RenderThreadImpl* render_thread = RenderThreadImpl::current();
-  if (render_thread && !info) {
+  // CreateDefaultURLLoaderFactoryBundle can't be called if (as in some tests)
+  // RenderThreadImpl::current is null.
+  if (RenderThreadImpl::current() && !info) {
     // This should only happen for a placeholder document or an initial empty
     // document cases.
     DCHECK(GetLoadingUrl().is_empty() ||
            GetLoadingUrl().spec() == url::kAboutBlankURL);
-    loader_factories->Update(render_thread->blink_platform_impl()
-                                 ->CreateDefaultURLLoaderFactoryBundle()
-                                 ->PassInterface());
+    loader_factories->Update(
+        CreateDefaultURLLoaderFactoryBundle()->PassInterface());
   }
 
   if (info) {

content/renderer/renderer_blink_platform_impl.cc

@@ -230,23 +230,6 @@ RendererBlinkPlatformImpl::WrapSharedURLLoaderFactory(
       std::move(factory));
 }
 
-scoped_refptr<ChildURLLoaderFactoryBundle>
-RendererBlinkPlatformImpl::CreateDefaultURLLoaderFactoryBundle() {
-  return base::MakeRefCounted<ChildURLLoaderFactoryBundle>(
-      base::BindOnce(&RendererBlinkPlatformImpl::CreateNetworkURLLoaderFactory,
-                     base::Unretained(this)));
-}
-
-mojo::PendingRemote<network::mojom::URLLoaderFactory>
-RendererBlinkPlatformImpl::CreateNetworkURLLoaderFactory() {
-  RenderThreadImpl* render_thread = RenderThreadImpl::current();
-  DCHECK(render_thread);
-  mojo::PendingRemote<network::mojom::URLLoaderFactory> factory_remote;
-  ChildThread::Get()->BindHostReceiver(
-      factory_remote.InitWithNewPipeAndPassReceiver());
-  return factory_remote;
-}
-
 void RendererBlinkPlatformImpl::SetDisplayThreadPriority(
     base::PlatformThreadId thread_id) {
 #if defined(OS_LINUX)

content/renderer/renderer_blink_platform_impl.h

@@ -56,7 +56,6 @@ class RasterContextProvider;
 }
 
 namespace content {
-class ChildURLLoaderFactoryBundle;
 
 class CONTENT_EXPORT RendererBlinkPlatformImpl : public BlinkPlatformImpl {
  public:
@@ -205,15 +204,6 @@ class CONTENT_EXPORT RendererBlinkPlatformImpl : public BlinkPlatformImpl {
 
   media::GpuVideoAcceleratorFactories* GetGpuFactories() override;
 
-  // Returns non-null.
-  // It is invalid to call this in an incomplete env where
-  // RenderThreadImpl::current() returns nullptr (e.g. in some tests).
-  scoped_refptr<ChildURLLoaderFactoryBundle>
-  CreateDefaultURLLoaderFactoryBundle();
-
-  mojo::PendingRemote<network::mojom::URLLoaderFactory>
-  CreateNetworkURLLoaderFactory();
-
   // Tells this platform that the renderer is locked to a site (i.e., a scheme
   // plus eTLD+1, such as https://google.com), or to a more specific origin.
   void SetIsLockedToSite();