Reland "[OutOfBlinkSandbox] Remove blink computation.""

This reland 367718cbad4ce4b5286d5493bd1720ef5626cc4d.
https://chromium-review.googlesource.com/c/chromium/src/+/2450093

This is a pure reland (+ fix merge conflict). No substantial changes.

There was two causes of the revert:
(1) Synchronous about:blank not initiated by the creator of a
frame/window:
https://docs.google.com/document/d/1KY0DCaoKjUPbOX28N9KWvBjbnAfQEIRTaLbZUq9EkK8
This is now prevented by:
https://chromium-review.googlesource.com/c/chromium/src/+/2667151

(2) Missing sandbox from CSP inherited from the initiator.
The patch is now using PolicyContainer to get it correctly:
https://chromium-review.googlesource.com/c/chromium/src/+/2741581

---

Both causes have a regression tests. They were added by:
https://chromium-review.googlesource.com/c/chromium/src/+/2648117

[email protected],[email protected]

Bug: 1041376
Change-Id: Icf8a6123c41d3f80c72ddc9c24e2b9c5f76ebc43
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2741587
Reviewed-by: Arthur Sonzogni <[email protected]>
Reviewed-by: Daniel Cheng <[email protected]>
Reviewed-by: Tommy Li <[email protected]>
Commit-Queue: Arthur Sonzogni <[email protected]>
Cr-Commit-Position: refs/heads/master@{#862021}
diff --git a/content/renderer/loader/navigation_body_loader_unittest.cc b/content/renderer/loader/navigation_body_loader_unittest.cc
index 5fe649f..1b2517a 100644
--- a/content/renderer/loader/navigation_body_loader_unittest.cc
+++ b/content/renderer/loader/navigation_body_loader_unittest.cc
@@ -51,6 +51,7 @@
     auto endpoints = network::mojom::URLLoaderClientEndpoints::New();
     endpoints->url_loader_client = client_remote_.BindNewPipeAndPassReceiver();
     blink::WebNavigationParams navigation_params;
+    navigation_params.sandbox_flags = network::mojom::WebSandboxFlags::kNone;
     auto common_params = CreateCommonNavigationParams();
     auto commit_params = CreateCommitNavigationParams();
     NavigationBodyLoader::FillNavigationParamsResponseAndBodyLoader(
@@ -331,6 +332,7 @@
   auto commit_params = CreateCommitNavigationParams();
 
   blink::WebNavigationParams navigation_params;
+  navigation_params.sandbox_flags = network::mojom::WebSandboxFlags::kNone;
   auto endpoints = network::mojom::URLLoaderClientEndpoints::New();
   mojo::ScopedDataPipeProducerHandle producer_handle;
   mojo::ScopedDataPipeConsumerHandle consumer_handle;