Revert "CSP: Enable out of blink enforcement of frame-ancestors."

This reverts commit 4ba80e19.

Reason for revert: crashes in content::AncestorThrottle::ProcessResponseImpl are in top 5 crashes on multiple platforms

Original change's description:
> CSP: Enable out of blink enforcement of frame-ancestors.
> 
> Bug: 1032139
> Change-Id: Iac59a5e6c8452da0cf7e7ebc549a10d8970cc8c4
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1988684
> Reviewed-by: Nasko Oskov <nasko@chromium.org>
> Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> Commit-Queue: Lucas Gadani <lfg@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#729823}

TBR=nasko@chromium.org,jam@chromium.org,lfg@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1032139,1041133
Change-Id: Id8eb28a5f2b6fc82ae94e0abb6f6d3c965bc6937
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2003553Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Commit-Queue: Jeremy Roman <jbroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732446}

services/network/public/cpp/features.cc

@@ -160,8 +160,8 @@ const base::Feature kDisableKeepaliveFetch{"DisableKeepaliveFetch",
 // When kOutOfBlinkFrameAncestors is enabled, the frame-ancestors
 // directive is parsed from the Content-Security-Policy header in the network
 // service and enforced in the browser.
-const base::Feature kOutOfBlinkFrameAncestors{"OutOfBlinkFrameAncestors",
-                                              base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kOutOfBlinkFrameAncestors{
+    "OutOfBlinkFrameAncestors", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Attach the origin of the destination URL to the "origin" header
 const base::Feature

third_party/blink/web_tests/TestExpectations

@@ -5642,7 +5642,7 @@ crbug.com/953153 external/wpt/speech-api/idlharness.window.html [ Pass Failure T
 # speculative navigation in the browser, and committing the navigation in the
 # renderer.
 crbug.com/838348 external/wpt/portals/csp/frame-src.sub.html [ Pass Crash ]
-crbug.com/838348 virtual/out-of-blink-frame-ancestors-disabled/external/wpt/portals/csp/frame-src.sub.html [ Pass Crash ]
+crbug.com/838348 virtual/out-of-blink-frame-ancestors/external/wpt/portals/csp/frame-src.sub.html [ Pass Crash ]
 
 # Sheriff 2019-04-17
 crbug.com/953591 [ Win ] css3/masking/mask-repeat-space-padding.html [ Pass Failure ]

third_party/blink/web_tests/VirtualTestSuites

@@ -645,9 +645,9 @@
     "args": ["--enable-blink-features=CSSModules"]
   },
   {
-    "prefix": "out-of-blink-frame-ancestors-disabled",
+    "prefix": "out-of-blink-frame-ancestors",
     "bases": ["external/wpt/content-security-policy/frame-ancestors", "external/wpt/portals/csp"],
-    "args": ["--disable-features=OutOfBlinkFrameAncestors"]
+    "args": ["--enable-features=OutOfBlinkFrameAncestors"]
   },
   {
     "prefix": "import-maps-disabled",

third_party/blink/web_tests/virtual/out-of-blink-frame-ancestors-disabled/README.md → third_party/blink/web_tests/virtual/out-of-blink-frame-ancestors/README.md

-This directory is for testing out-of-blink frame-ancestors CSP enforcement
-disabled.
+This directory is for testing out-of-blink frame-ancestors CSP enforcement.
 
-This test suite runs the tests with --disable-features=OutOfBlinkFrameAncestors.
+This test suite runs the tests with --enable-features=OutOfBlinkFrameAncestors.
 
 - https://crbug.com/759184

third_party/blink/web_tests/virtual/out-of-blink-frame-ancestors/external/wpt/portals/csp/frame-ancestors.sub-expected.txt

+This is a testharness.js-based test.
+PASS Violation report status OK.
+Harness: the test ran to completion.
+