Add NetworkService support for CefURLRequest (see issue #2622).

Requests created using CefURLRequest::Create are not associated with a
browser/frame. When originating from the render process these requests cannot be
intercepted and consequently only http(s) and blob requests are supported. To
work around this limitation a new CefFrame::CreateURLRequest method has been
added that allows the request to be associated with that browser/frame for
interception purposes.

This change also fixes an issue with the NetworkService implementation where
redirected requests could result in two parallel requests being sent to the
target server.

To test: URLRequestTest.* tests pass with NetworkService enabled.

patch/patches/component_build.patch

@@ -12,6 +12,27 @@ index 864f2a5a315a..78b71d523e86 100644
   public:
    explicit ContentServiceManagerMainDelegate(const ContentMainParams& params);
    ~ContentServiceManagerMainDelegate() override;
+diff --git content/browser/devtools/devtools_instrumentation.h content/browser/devtools/devtools_instrumentation.h
+index 605e388043ac..4566dd95f0b8 100644
+--- content/browser/devtools/devtools_instrumentation.h
++++ content/browser/devtools/devtools_instrumentation.h
+@@ -12,6 +12,7 @@
+ #include <vector>
+ 
+ #include "base/optional.h"
++#include "content/common/content_export.h"
+ #include "content/common/navigation_params.mojom.h"
+ #include "content/public/browser/certificate_request_result_type.h"
+ #include "services/network/public/mojom/url_loader_factory.mojom.h"
+@@ -49,7 +50,7 @@ void ApplyNetworkRequestOverrides(FrameTreeNode* frame_tree_node,
+                                   mojom::BeginNavigationParams* begin_params,
+                                   bool* report_raw_headers);
+ 
+-bool WillCreateURLLoaderFactory(
++CONTENT_EXPORT bool WillCreateURLLoaderFactory(
+     RenderFrameHostImpl* rfh,
+     bool is_navigation,
+     bool is_download,
 diff --git content/browser/renderer_host/input/synthetic_gesture_target_base.h content/browser/renderer_host/input/synthetic_gesture_target_base.h
 index 33a2d55e47ac..1700b3df2468 100644
 --- content/browser/renderer_host/input/synthetic_gesture_target_base.h