DocumentChannel works for most protocols now, so we should enable as many as we can and use a list of types that we explicitly disallow instead.

Without DocumentChannel, nsExtProtocolChannel::OpenURL calls into nsExternalHelperAppService::LoadURI in the content process.
We then manually forward this to the parent process over PContent, create a RemoteWindowContext around the browser parent, and then call LoadURI again.

With DocumemntChannel, the nsExtProtocolChannel already lives in the parent, so we just need to provide a RemoteWindowContext directly (that the code accesses via GetInterface on the callbacks).

Depends on D54246

Previously this error occurred synchronously during AsyncOpen, and we handled it there.
With DocumentChannel we don't find out until it's handled in the parent, so the error is returned to the docshell via a failed status on the request.

Depends on D54247

Looks like this can sometimes fail with moz-extension URIs, so we shouldn't crash

Depends on D54248

Depends on D54249

Without DocumentChannel, we create the real channel in the content process, which fully resolves the URI and so tabbrowser can see this as the URI.

With DocumentChannel, we only create the real channel in the parent, so the initial onStateChange only has the provided URI (which is still about:<page>).

I'm not sure if this is the best fix though.

Other options:

• Create a temporary real channel in DocumentChannelChild just to get the resolved URI correct.
• Avoid firing onStateChange until DocumentChannel responds with the resolved URI.
• Add a new way to resolve just the URI without creating a channel.

Depends on D54250

Changing to M4.1 because it blocks a M4.1 mochitests bug.

Backed out 6 changesets (bug 1598516) for Mn and pgo failures

Backout: https://hg.mozilla.org/integration/autoland/rev/af6939203f160e17a6c0eb21593258c907cdddea

Failure push: https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=63a84cdfd9371b0af1660123a93e5f050608dd9b

Failure log pgo: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=278146631&repo=autoland&lineNumber=480
Failure log Mn: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=278120476&repo=autoland&lineNumber=51864

Depends on D54251

Depends on D55604

Backed out 8 changesets (bug 1598516) for build bustage at ParentChannelListener.cpp on a CLOSED TREE.

Backout link: https://hg.mozilla.org/integration/autoland/rev/dd7bf37dadb0f64904181900a3861d4424c9c32e

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&revision=7ac1b091aa5f91ddfac46ecdfdf3f14a2e5540d0&selectedJob=279401156

Log link: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=279401156&repo=autoland&lineNumber=18869

Log snippet:

[task 2019-12-03T19:44:49.673Z] 19:44:49 INFO - media/webrtc/signaling/src/sdp/RsdparsaSdp.o
[task 2019-12-03T19:44:49.673Z] 19:44:49 INFO - make[4]: Leaving directory '/builds/worker/workspace/build/src/obj-firefox/media/webrtc/signaling/src/sdp'
[task 2019-12-03T19:44:49.688Z] 19:44:49 INFO - make[4]: Entering directory '/builds/worker/workspace/build/src/obj-firefox/media/webrtc/signaling/gtest'
[task 2019-12-03T19:44:49.688Z] 19:44:49 INFO - media/webrtc/signaling/gtest/rtpsources_unittests.o
[task 2019-12-03T19:44:49.688Z] 19:44:49 INFO - make[4]: Leaving directory '/builds/worker/workspace/build/src/obj-firefox/media/webrtc/signaling/gtest'
[task 2019-12-03T19:44:49.809Z] 19:44:49 INFO - make[4]: Entering directory '/builds/worker/workspace/build/src/obj-firefox/netwerk/protocol/http'
[task 2019-12-03T19:44:49.811Z] 19:44:49 INFO - /builds/worker/fetches/sccache/sccache /builds/worker/fetches/clang/bin/clang++ -std=gnu++17 -m32 -o Unified_cpp_protocol_http2.o -c -I/builds/worker/workspace/build/src/obj-firefox/dist/stl_wrappers -I/builds/worker/workspace/build/src/obj-firefox/dist/system_wrappers -include /builds/worker/workspace/build/src/config/gcc_hidden.h -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fstack-protector-strong -DDEBUG=1 -DOS_POSIX=1 -DOS_LINUX=1 -DSTATIC_EXPORTABLE_JS_API -DMOZ_HAS_MOZGLUE -DMOZILLA_INTERNAL_API -DIMPL_LIBXUL -I/builds/worker/workspace/build/src/netwerk/protocol/http -I/builds/worker/workspace/build/src/obj-firefox/netwerk/protocol/http -I/builds/worker/workspace/build/src/obj-firefox/ipc/ipdl/_ipdlheaders -I/builds/worker/workspace/build/src/ipc/chromium/src -I/builds/worker/workspace/build/src/ipc/glue -I/builds/worker/workspace/build/src/dom/base -I/builds/worker/workspace/build/src/extensions/auth -I/builds/worker/workspace/build/src/netwerk/base -I/builds/worker/workspace/build/src/netwerk/cookie -I/builds/worker/workspace/build/src/netwerk/ipc -I/builds/worker/workspace/build/src/netwerk/socket/neqo_glue -I/builds/worker/workspace/build/src/netwerk/url-classifier -I/builds/worker/workspace/build/src/obj-firefox/dist/include -I/builds/worker/workspace/build/src/obj-firefox/dist/include/nspr -I/builds/worker/workspace/build/src/obj-firefox/dist/include/nss -fPIC -DMOZILLA_CLIENT -include /builds/worker/workspace/build/src/obj-firefox/mozilla-config.h -Qunused-arguments -Qunused-arguments -Wall -Wbitfield-enum-conversion -Wempty-body -Wignored-qualifiers -Woverloaded-virtual -Wpointer-arith -Wshadow-field-in-constructor-modified -Wsign-compare -Wtype-limits -Wunreachable-code -Wunreachable-code-return -Wwrite-strings -Wno-invalid-offsetof -Wclass-varargs -Wfloat-overflow-conversion -Wfloat-zero-conversion -Wloop-analysis -Wc++2a-compat -Wcomma -Wimplicit-fallthrough -Werror=non-literal-null-conversion -Wstring-conversion -Wtautological-overlap-compare -Wtautological-unsigned-enum-zero-compare -Wtautological-unsigned-zero-compare -Wno-error=tautological-type-limit-compare -Wno-inline-new-delete -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=backend-plugin -Wno-error=return-std-move -Wno-error=atomic-alignment -Wformat -Wformat-security -Wno-gnu-zero-variadic-macro-arguments -Wno-unknown-warning-option -Wno-return-type-c-linkage -D_GLIBCXX_USE_CXX11_ABI=0 -fno-sized-deallocation -fno-aligned-new -fcrash-diagnostics-dir=/builds/worker/artifacts -march=pentium-m -msse -msse2 -mfpmath=sse -fno-exceptions -fno-strict-aliasing -fno-rtti -ffunction-sections -fdata-sections -fno-exceptions -fno-math-errno -pthread -pipe -g -Xclang -load -Xclang /builds/worker/workspace/build/src/obj-firefox/build/clang-plugin/libclang-plugin.so -Xclang -add-plugin -Xclang moz-check -Os -fno-omit-frame-pointer -funwind-tables -Werror -MD -MP -MF .deps/Unified_cpp_protocol_http2.o.pp Unified_cpp_protocol_http2.cpp
[task 2019-12-03T19:44:49.811Z] 19:44:49 INFO - In file included from Unified_cpp_protocol_http2.cpp:11:
[task 2019-12-03T19:44:49.812Z] 19:44:49 ERROR - /builds/worker/workspace/build/src/netwerk/protocol/http/ParentChannelListener.cpp:163:13: error: unknown type name 'RemoteWindowContext'; did you mean 'dom::RemoteWindowContext'?
[task 2019-12-03T19:44:49.812Z] 19:44:49 INFO - new RemoteWindowContext(mBrowserParent));
[task 2019-12-03T19:44:49.813Z] 19:44:49 INFO - ^~~~~~~~~~~~~~~~~~~
[task 2019-12-03T19:44:49.813Z] 19:44:49 INFO - dom::RemoteWindowContext
[task 2019-12-03T19:44:49.813Z] 19:44:49 INFO - /builds/worker/workspace/build/src/obj-firefox/dist/include/mozilla/dom/ContentParent.h:1415:7: note: 'dom::RemoteWindowContext' declared here
[task 2019-12-03T19:44:49.814Z] 19:44:49 INFO - class RemoteWindowContext final : public nsIRemoteWindowContext,
[task 2019-12-03T19:44:49.814Z] 19:44:49 INFO - ^
[task 2019-12-03T19:44:49.814Z] 19:44:49 INFO - 1 error generated.
[task 2019-12-03T19:44:49.815Z] 19:44:49 INFO - /builds/worker/workspace/build/src/config/rules.mk:804: recipe for target 'Unified_cpp_protocol_http2.o' failed
[task 2019-12-03T19:44:49.815Z] 19:44:49 ERROR - make[4]: *** [Unified_cpp_protocol_http2.o] Error 1
[task 2019-12-03T19:44:49.815Z] 19:44:49 INFO - make[4]: Leaving directory '/builds/worker/workspace/build/src/obj-firefox/netwerk/protocol/http'
[task 2019-12-03T19:44:49.815Z] 19:44:49 INFO - /builds/worker/workspace/build/src/config/recurse.mk:74: recipe for target 'netwerk/protocol/http/target-objects' failed
[task 2019-12-03T19:44:49.816Z] 19:44:49 ERROR - make[3]: *** [netwerk/protocol/http/target-objects] Error 2
[task 2019-12-03T19:44:49.816Z] 19:44:49 INFO - make[3]: *** Waiting for unfinished jobs....
[task 2019-12-03T19:44:49.816Z] 19:44:49 INFO - make[4]: Entering directory '/builds/worker/workspace/build/src/obj-firefox/media/webrtc/signaling/gtest'
[task 2019-12-03T19:44:49.816Z] 19:44:49 INFO - media/webrtc/signaling/gtest/sdp_unittests.o

Backed out 8 changesets (Bug 1598516) for run startup hangs

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&searchStr=linux%2Crun&fromchange=d2f8a8875708e694346e9ec7b5d5d0761e3662ca&tochange=09111adf1bd1502668e50d0983afc0bc97b99694&selectedJob=279424792

Backout link: https://hg.mozilla.org/integration/autoland/rev/9cead615dadbd3652e527c97f05f55434415729a

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=279424792&repo=autoland&lineNumber=310

[task 2019-12-03T21:29:09.584Z] Installing setuptools, pip, wheel...done.
[task 2019-12-03T21:29:10.597Z] running build_ext
[task 2019-12-03T21:29:10.597Z] building 'psutil._psutil_linux' extension
[task 2019-12-03T21:29:10.597Z] creating build
[task 2019-12-03T21:29:10.597Z] creating build/temp.linux-x86_64-2.7
[task 2019-12-03T21:29:10.597Z] creating build/temp.linux-x86_64-2.7/psutil
[task 2019-12-03T21:29:10.597Z] x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -DPSUTIL_POSIX=1 -DPSUTIL_VERSION=563 -DPSUTIL_LINUX=1 -I/usr/include/python2.7 -c psutil/_psutil_common.c -o build/temp.linux-x86_64-2.7/psutil/_psutil_common.o
[task 2019-12-03T21:29:10.597Z] x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -DPSUTIL_POSIX=1 -DPSUTIL_VERSION=563 -DPSUTIL_LINUX=1 -I/usr/include/python2.7 -c psutil/_psutil_posix.c -o build/temp.linux-x86_64-2.7/psutil/_psutil_posix.o
[task 2019-12-03T21:29:10.597Z] x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -DPSUTIL_POSIX=1 -DPSUTIL_VERSION=563 -DPSUTIL_LINUX=1 -I/usr/include/python2.7 -c psutil/_psutil_linux.c -o build/temp.linux-x86_64-2.7/psutil/_psutil_linux.o
[task 2019-12-03T21:29:10.597Z] creating build/lib.linux-x86_64-2.7
[task 2019-12-03T21:29:10.597Z] creating build/lib.linux-x86_64-2.7/psutil
[task 2019-12-03T21:29:10.597Z] x86_64-linux-gnu-gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-z,relro -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security -Wl,-z,relro -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security build/temp.linux-x86_64-2.7/psutil/_psutil_common.o build/temp.linux-x86_64-2.7/psutil/_psutil_posix.o build/temp.linux-x86_64-2.7/psutil/_psutil_linux.o -o build/lib.linux-x86_64-2.7/psutil/_psutil_linux.so
[task 2019-12-03T21:29:10.597Z] building 'psutil._psutil_posix' extension
[task 2019-12-03T21:29:10.597Z] x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -DPSUTIL_POSIX=1 -DPSUTIL_VERSION=563 -DPSUTIL_LINUX=1 -I/usr/include/python2.7 -c psutil/_psutil_common.c -o build/temp.linux-x86_64-2.7/psutil/_psutil_common.o
[task 2019-12-03T21:29:10.597Z] x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -DPSUTIL_POSIX=1 -DPSUTIL_VERSION=563 -DPSUTIL_LINUX=1 -I/usr/include/python2.7 -c psutil/_psutil_posix.c -o build/temp.linux-x86_64-2.7/psutil/_psutil_posix.o
[task 2019-12-03T21:29:10.597Z] x86_64-linux-gnu-gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-z,relro -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security -Wl,-z,relro -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-2.7.13=. -fstack-protector-strong -Wformat -Werror=format-security build/temp.linux-x86_64-2.7/psutil/_psutil_common.o build/temp.linux-x86_64-2.7/psutil/_psutil_posix.o -o build/lib.linux-x86_64-2.7/psutil/_psutil_posix.so
[task 2019-12-03T21:29:10.597Z] copying build/lib.linux-x86_64-2.7/psutil/_psutil_linux.so -> psutil
[task 2019-12-03T21:29:10.597Z] copying build/lib.linux-x86_64-2.7/psutil/_psutil_posix.so -> psutil
[task 2019-12-03T21:29:10.597Z]
[task 2019-12-03T21:29:10.597Z] Error processing command. Ignoring because optional. (optional:packages.txt:comm/build/virtualenv_packages.txt)
[taskcluster:error] Task timeout after 1200 seconds. Force killing container.
[taskcluster 2019-12-03 21:48:37.433Z] === Task Finished ===
[taskcluster 2019-12-03 21:48:37.434Z] Unsuccessful task run with exit code: -1 completed in 1218.749 seconds

https://hg.mozilla.org/mozilla-central/rev/9a9051421265
https://hg.mozilla.org/mozilla-central/rev/fd3b7af6c012
https://hg.mozilla.org/mozilla-central/rev/3422602420a0
https://hg.mozilla.org/mozilla-central/rev/dfb2624a9857
https://hg.mozilla.org/mozilla-central/rev/abece0ceac3d
https://hg.mozilla.org/mozilla-central/rev/dfee5b58e921
https://hg.mozilla.org/mozilla-central/rev/e100ba2fc666
https://hg.mozilla.org/mozilla-central/rev/94663676950d