Windows and OSX only? https://treeherder.mozilla.org/logviewer.html#?job_id=6442980&repo=try 00:36:34 INFO - 811 INFO TEST-START | browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js 00:36:34 INFO - 812 INFO checking window state 00:36:34 INFO - 813 INFO Entering test setup 00:36:34 INFO - 814 INFO TEST-UNEXPECTED-FAIL | browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js | Uncaught exception - [Exception... "Not enough arguments [nsIObserverService.addObserver]" nsresult: "0x80570001 (NS_ERROR_XPC_NOT_ENOUGH_ARGS)" location: "JS frame :: chrome://mochitests/content/browser/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js :: setup :: line 112" data: no] 00:36:34 INFO - Stack trace: 00:36:34 INFO - setup@chrome://mochitests/content/browser/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js:112:3 00:36:34 INFO - Tester_execTest@chrome://mochikit/content/browser-test.js:739:9 00:36:34 INFO - Tester.prototype.nextTest</<@chrome://mochikit/content/browser-test.js:662:7 00:36:34 INFO - SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:752:59 00:36:34 INFO - Tester_execTest@chrome://mochikit/content/browser-test.js:739:9 00:36:34 INFO - Tester.prototype.nextTest</<@chrome://mochikit/content/browser-test.js:662:7 00:36:34 INFO - SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:752:59 00:36:34 INFO - 815 INFO Leaving test setup 00:36:34 INFO - 816 INFO Entering test testChromeHearsPluginCrashFirst 00:36:35 INFO - JavaScript error: resource://gre/modules/RemoteAddonsChild.jsm, line 27: TypeError: invalid 'in' operand dict 00:36:35 INFO - 817 INFO Console message: [JavaScript Warning: "Unknown property 'text-emphasis'. Declaration dropped." {file: "resource://gre-resources/html.css" line: 807 column: 17 source: " text-emphasis: none;"}] 00:36:35 INFO - 818 INFO Console message: [JavaScript Error: "invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - 819 INFO Console message: [JavaScript Error: "invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - 820 INFO Console message: [JavaScript Error: "invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - 821 INFO Console message: [JavaScript Error: "TypeError: invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - ###!!! [Parent][MessageChannel::Call] Error: Channel error: cannot send/recv 00:36:35 INFO - ###!!! [Parent][MessageChannel] Error: Channel error: cannot send/recv 00:36:35 INFO - 822 INFO TEST-PASS | browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js | Should have been showing crash report UI 00:36:35 INFO - 823 INFO Leaving test testChromeHearsPluginCrashFirst 00:36:35 INFO - 824 INFO Entering test testContentHearsCrashFirst 00:36:35 INFO - 825 INFO Console message: [JavaScript Warning: "unsafe CPOW usage" {file: "resource:///modules/sessionstore/TabState.jsm" line: 96}] 00:36:35 INFO - 826 INFO Console message: [JavaScript Warning: "unsafe CPOW usage" {file: "resource:///modules/sessionstore/TabState.jsm" line: 96}] 00:36:35 INFO - [Child 3816] WARNING: pipe error: 109: file c:/builds/moz2_slave/try-w64-0000000000000000000000/build/src/ipc/chromium/src/chrome/common/ipc_channel_win.cc, line 305 00:36:35 INFO - [Child 3816] WARNING: pipe error: 109: file c:/builds/moz2_slave/try-w64-0000000000000000000000/build/src/ipc/chromium/src/chrome/common/ipc_channel_win.cc, line 305 00:36:35 INFO - JavaScript error: resource://gre/modules/RemoteAddonsChild.jsm, line 27: TypeError: invalid 'in' operand dict 00:36:35 INFO - 827 INFO Console message: [JavaScript Warning: "Unknown property 'text-emphasis'. Declaration dropped." {file: "resource://gre-resources/html.css" line: 807 column: 17 source: " text-emphasis: none;"}] 00:36:35 INFO - 828 INFO Console message: [JavaScript Error: "invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - 829 INFO Console message: [JavaScript Error: "invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - 830 INFO Console message: [JavaScript Error: "invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - 831 INFO Console message: [JavaScript Error: "TypeError: invalid 'in' operand dict" {file: "resource://gre/modules/RemoteAddonsChild.jsm" line: 27}] 00:36:35 INFO - ###!!! [Parent][MessageChannel::Call] Error: Channel error: cannot send/recv 00:36:35 INFO - ###!!! [Parent][MessageChannel] Error: Channel error: cannot send/recv 00:36:35 INFO - 832 INFO TEST-UNEXPECTED-FAIL | browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js | Should not yet be showing crash report UI - 00:36:35 INFO - Stack trace: 00:36:35 INFO - chrome://mochitests/content/browser/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js:testContentHearsCrashFirst:234 00:36:35 INFO - self-hosted:InterpretGeneratorResume:717 00:36:35 INFO - self-hosted:next:625 00:36:35 INFO - Handler.prototype.process@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:867:23 00:36:35 INFO - this.PromiseWalker.walkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:746:7 00:36:35 INFO - this.PromiseWalker.scheduleWalkerLoop/<@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:688:37 00:36:35 INFO - Promise*this.PromiseWalker.scheduleWalkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:688:5 00:36:35 INFO - this.PromiseWalker.schedulePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:709:7 00:36:35 INFO - this.PromiseWalker.completePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:671:7 00:36:35 INFO - TaskImpl_run@resource://gre/modules/Task.jsm:319:13 00:36:35 INFO - Promise*closeWindow@resource://testing-common/BrowserTestUtils.jsm:158:1 00:36:35 INFO - testChromeHearsPluginCrashFirst@chrome://mochitests/content/browser/browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js:184:9 00:36:35 INFO - TaskImpl_run@resource://gre/modules/Task.jsm:314:40 00:36:35 INFO - Handler.prototype.process@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:867:23 00:36:35 INFO - this.PromiseWalker.walkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:746:7 00:36:35 INFO - this.PromiseWalker.scheduleWalkerLoop/<@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:688:37 00:36:35 INFO - Promise*this.PromiseWalker.scheduleWalkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:688:5 00:36:35 INFO - this.PromiseWalker.schedulePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:709:7 00:36:35 INFO - this.PromiseWalker.completePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:671:7 00:36:35 INFO - receiveMessage@resource://testing-common/ContentTask.jsm:91:7 00:36:35 INFO - 833 INFO TEST-PASS | browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js | Should have been showing crash report UI 00:36:36 INFO - 834 INFO Leaving test testContentHearsCrashFirst 00:36:36 INFO - 835 INFO Console message: [JavaScript Warning: "unsafe CPOW usage" {file: "resource:///modules/sessionstore/TabState.jsm" line: 96}] 00:36:36 INFO - 836 INFO Console message: [JavaScript Warning: "unsafe CPOW usage" {file: "resource:///modules/sessionstore/TabState.jsm" line: 96}] 00:36:36 INFO - MEMORY STAT vsize after test: 818921472 00:36:36 INFO - MEMORY STAT vsizeMaxContiguous after test: 8643901849600 00:36:36 INFO - MEMORY STAT residentFast after test: 333836288 00:36:36 INFO - MEMORY STAT heapAllocated after test: 106348372 00:36:36 INFO - 837 INFO TEST-OK | browser/base/content/test/plugins/browser_pluginCrashReportNonDeterminism.js | took 1241ms

Hrm. Oddly, this seems to be failing out on Aurora because I didn't pass in the third argument to addObserver. Strange how this passed without a problem on central. Try push with the third argument added: https://treeherder.mozilla.org/#/jobs?repo=try&revision=cf1886b5d6a0

Not the greatest try push I've ever seen, but it certainly addresses the issue addObserver issue with browser_pluginCrashReportNonDeterminism.js. Pushing with r=test-only-change. remote: https://hg.mozilla.org/integration/fx-team/rev/5c4db3f21e9f