This is observed at least since 2018-08-20, so it's unlikely that this is a
very recent regression. Perhaps the test is inherently flaky.

I'm going to disable the test.

The CL disabling the test is in CQ:
https://chromium-review.googlesource.com/c/chromium/src/+/1195245

+tedchoc for triage.

Failure log:

java.lang.AssertionError: Form resubmission warning dialog was not dismissed correctly. expected null, but was:<oe@429441c0>
	at org.junit.Assert.fail(PG:88)
	at org.junit.Assert.failNotNull(PG:755)
	at org.junit.Assert.assertNull(PG:737)
	at org.chromium.chrome.browser.RepostFormWarningTest.testFormResubmissionContinue(PG:100)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:515)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(PG:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(PG:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(PG:52)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(PG:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(PG:26)
	at org.chromium.base.test.ScreenshotOnFailureStatement.evaluate(PG:37)
	at org.junit.internal.runners.statements.RunAfters.evaluate(PG:27)
	at org.chromium.chrome.test.ChromeActivityTestRule$1.evaluate(PG:116)
	at android.support.test.internal.statement.UiThreadStatement.evaluate(PG:55)
	at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(PG:270)
	at org.junit.rules.ExternalResource$1.evaluate(PG:48)
	at org.junit.rules.RunRules.evaluate(PG:20)
	at org.junit.runners.ParentRunner.runLeaf(PG:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(PG:78)
	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(PG:237)
	at org.chromium.base.test.BaseJUnit4ClassRunner.runChild(PG:48)
	at org.junit.runners.ParentRunner$3.run(PG:290)
	at org.junit.runners.ParentRunner$1.schedule(PG:71)
	at org.junit.runners.ParentRunner.runChildren(PG:288)
	at org.junit.runners.ParentRunner.access$000(PG:58)
	at org.junit.runners.ParentRunner$2.evaluate(PG:268)
	at org.junit.runners.ParentRunner.run(PG:363)
	at org.chromium.base.test.BaseJUnit4ClassRunner.run(PG:220)
	at org.junit.runners.Suite.runChild(PG:128)
	at org.junit.runners.Suite.runChild(PG:27)
	at org.junit.runners.ParentRunner$3.run(PG:290)
	at org.junit.runners.ParentRunner$1.schedule(PG:71)
	at org.junit.runners.ParentRunner.runChildren(PG:288)
	at org.junit.runners.ParentRunner.access$000(PG:58)
	at org.junit.runners.ParentRunner$2.evaluate(PG:268)
	at org.junit.runners.ParentRunner.run(PG:363)
	at org.junit.runner.JUnitCore.run(PG:137)
	at org.junit.runner.JUnitCore.run(PG:115)
	at android.support.test.internal.runner.TestExecutor.execute(PG:59)
	at android.support.test.runner.AndroidJUnitRunner.onStart(PG:262)
	at org.chromium.base.test.BaseChromiumAndroidJUnitRunner.onStart(PG:125)
	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)
Searching for native crashes in: /b/swarming/w/ityRu9dh/tmp_8O96p
Unknown Android release, consider passing --packed-lib.
Reading Android symbols from: /b/swarming/w/ir
Searching for Chrome symbols from within: /b/swarming/w/ir/out/Release/lib.unstripped:/b/swarming/w/ir/out/Release

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0104c6b8943770253974aace5064422bb45f008d

commit 0104c6b8943770253974aace5064422bb45f008d
Author: Yuta Kitamura <yutak@chromium.org>
Date: Wed Aug 29 07:07:51 2018

Disable RepostFormWarningTest#testFormResubmissionContinue.

This test is flaky.

TBR=nednguyen@chromium.org,tedchoc@chromium.org

Bug: 878651
Change-Id: I4e12fa940cd8044ee0c20e15fe18e8a5192f1779
Reviewed-on: https://chromium-review.googlesource.com/1195245
Commit-Queue: Yuta Kitamura <yutak@chromium.org>
Reviewed-by: Yuta Kitamura <yutak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587029}
[modify] https://crrev.com/0104c6b8943770253974aace5064422bb45f008d/chrome/android/javatests/src/org/chromium/chrome/browser/RepostFormWarningTest.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bf9fca74800e2fbeac05b5a6ed7437a8cc29adea

commit bf9fca74800e2fbeac05b5a6ed7437a8cc29adea
Author: Ted Choc <tedchoc@google.com>
Date: Wed Aug 29 22:16:33 2018

Attempt to deflake ReportFormWarningTest#testFormResubmissionContinue

I ran the test locally a 100 times and could not repro, but I
found we weren't clearing out the dialog reference in the
dismiss calls (just the dialog on dismiss handler), so this
makes it happen always.  This also adds the logic to wait for the
dialog to be null to avoid any races in the android handling of
dialog dismissal.

BUG=878651

Change-Id: Id4ae17479b9e4ad29b67e6fd9da9673ddc8a7ee6
Reviewed-on: https://chromium-review.googlesource.com/1195744
Reviewed-by: Pedro Amaral <amaralp@chromium.org>
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587322}
[modify] https://crrev.com/bf9fca74800e2fbeac05b5a6ed7437a8cc29adea/chrome/android/java/src/org/chromium/chrome/browser/RepostFormWarningDialog.java
[modify] https://crrev.com/bf9fca74800e2fbeac05b5a6ed7437a8cc29adea/chrome/android/javatests/src/org/chromium/chrome/browser/RepostFormWarningTest.java