RemoteWebNavigation is expected to pass a serialized principal, so the default null principal should be serialized as well.

For improved security, default to a null triggering principal for GeckoView.loadUri calls, except when loading certain privileged schemes such as "resource" and "file".

The use of <iframe mozbrowser> in test_saveHeapSnapshot_e10s_01.html has implicitly depended on the "network.disable.ipc.security" pref set to false, which is the default for desktop and not applicable for Fennec. With the new mobile test harness, this pref needs to be set explicitly by the test.

Pushed by nchen@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/abf2e04e30e4 1. Serialize default null principal in RemoteWebNavigation; r=jkt https://hg.mozilla.org/integration/autoland/rev/daf7ced3bbcc 2. Default to null triggering principal for GeckoView.loadUri; r=esawin https://hg.mozilla.org/integration/autoland/rev/70505741627f 3. Disable Necko IPC security for test_saveHeapSnapshot_e10s_01; r=fitzgen

Backed out 3 changesets (bug 1496220) for browser_e10s_switchbrowser.js and test_findbar.xul failures push that caused the backout: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&selectedJob=204622953&revision=70505741627fe29e79facb7fab0e3297320f0421 failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed,busted,exception&classifiedState=unclassified&selectedJob=204622953&revision=70505741627fe29e79facb7fab0e3297320f0421&failure_classification_id=2 backout: https://hg.mozilla.org/integration/autoland/rev/0bd0dc3c8183e67a37fd08617a5b456049bf444b

nsIWebNavigation.loadURI actually has an optional triggering principal parameter that RemoteWebNavigation hasn't implemented. This patch adds the extra parameter to RemoteWebNavigation's implementation so triggering principals are passed properly when loadURI is called with a triggering principal.

When defaulting to a null triggering principal, these tests would fail when loaded remotely. This patch adds explicit system triggering principal to the loadURI calls.

Pushed by nchen@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/c4a8a6256d7f 1. Serialize default null principal in RemoteWebNavigation; r=jkt https://hg.mozilla.org/integration/autoland/rev/670b75f8446f 2. Default to null triggering principal for GeckoView.loadUri; r=esawin https://hg.mozilla.org/integration/autoland/rev/7b5505d44965 3. Disable Necko IPC security for test_saveHeapSnapshot_e10s_01; r=fitzgen https://hg.mozilla.org/integration/autoland/rev/bc592bed0522 4. Add triggering principal parameter to RemoteWebNavigation.loadURI; r=jkt https://hg.mozilla.org/integration/autoland/rev/2c1353f4a3f5 5. Pass explicit triggering principal in more places; r=jkt

Backout by dvarga@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/47e77fc9d699 Backed out 5 changesets for chrome failure at toolkit/content/tests/chrome/test_findbar_events.xul. on a CLOSED TREE

Pushed by nchen@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/243b8450ba00 1. Serialize default null principal in RemoteWebNavigation; r=jkt https://hg.mozilla.org/integration/mozilla-inbound/rev/b4464cd48336 2. Default to null triggering principal for GeckoView.loadUri; r=esawin https://hg.mozilla.org/integration/mozilla-inbound/rev/1f98cec81e6b 3. Disable Necko IPC security for test_saveHeapSnapshot_e10s_01; r=fitzgen https://hg.mozilla.org/integration/mozilla-inbound/rev/0fb606cf70a0 4. Add triggering principal parameter to RemoteWebNavigation.loadURI; r=jkt https://hg.mozilla.org/integration/mozilla-inbound/rev/cd2a304f5fe9 5. Pass explicit triggering principal in more places; r=jkt

https://hg.mozilla.org/mozilla-central/rev/243b8450ba00 https://hg.mozilla.org/mozilla-central/rev/b4464cd48336 https://hg.mozilla.org/mozilla-central/rev/1f98cec81e6b https://hg.mozilla.org/mozilla-central/rev/0fb606cf70a0 https://hg.mozilla.org/mozilla-central/rev/cd2a304f5fe9

64=wontfix because we don't need to uplift these test fixes.

status-geckoview64=wontfix