Update worker tests to avoid hitting memory limits.

https://chromium-review.googlesource.com/c/chromium/src/+/641992,
the fix for crbug.com/752185, causes the following layout tests:

* fast/workers/worker-exception-during-navigation.html
* fast/workers/worker-multi-startup.html
* http/tests/workers/terminate-during-sync-operation-file.html
* http/tests/workers/terminate-during-sync-operation-filesystem.html
* virtual/mojo-loading/http/tests/workers/terminate-during-sync-operation-file.html
* virtual/mojo-loading/http/tests/workers/terminate-during-sync-operation-filesystem.html

to hit per-process memory limits on Linux. Fix by reducing the number
of workers created in the tests from 30 to 20.

See https://bugs.chromium.org/p/chromium/issues/detail?id=752185#c61
for an explanation.

BUG=752185
TEST=Layout tests pass with related change.

Change-Id: Ic0ebaaaad01ce05be5ca88214172d6141f57c2f0
Reviewed-on: https://chromium-review.googlesource.com/685718
Commit-Queue: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505032}

third_party/WebKit/LayoutTests/fast/workers/worker-exception-during-navigation.html

@@ -22,16 +22,16 @@ function test() {
     }
 
     // Create sufficiently large number of workers in hopes that one of the exceptions they throw will be processed in short time interval in
-    // which it could case the crash from the bug.
+    // which it could cause the crash from the bug.
     var workers = [];
     console.log("Creating the workers.")
-    for (var i = 0; i < 30; i++) {
+    for (var i = 0; i < 20; i++) {
         setTimeout(function() {
             try {
                 var worker = new Worker('resources/worker-exception.js');
                 worker.onerror = function(evt) {
-                    // The number of worker exceptions that will be catched is not deterministic,
-                    // so let's make sire the excption is not written to console to have deterministic text output.
+                    // The number of worker exceptions that will be caught is not deterministic,
+                    // so let's make sure the exception is not written to console to have deterministic text output.
                     evt.preventDefault();
                 };
                 workers.push(worker);

third_party/WebKit/LayoutTests/fast/workers/worker-multi-startup-expected.txt

@@ -20,15 +20,5 @@ SUCCESS: Worker context initialized
 SUCCESS: Worker context initialized
 SUCCESS: Worker context initialized
 SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
-SUCCESS: Worker context initialized
 DONE
 

third_party/WebKit/LayoutTests/fast/workers/worker-multi-startup.html

@@ -13,7 +13,7 @@ function log(message)
     document.getElementById("result").innerHTML += message + "<br>";
 }
 
-totalWorkers = 30;
+totalWorkers = 20;
 replies = 0;
 
 for (var i = 0; i < totalWorkers; i++) {

third_party/WebKit/LayoutTests/http/tests/workers/resources/terminate-during-sync-operation.js

 var workersStarted;
 var workersClosed;
-// 30 workers seemed to cause the crash to happen frequently.
-var workers = new Array(30);
+// More than 20 workers causes OOM crashes (hitting RLIMIT_DATA memory limits)
+// on Linux.
+var workers = new Array(20);
 
 function startWorkers(operationName)
 {

third_party/WebKit/LayoutTests/http/tests/workers/terminate-during-sync-operation-file-expected.txt

@@ -23,16 +23,6 @@ Started worker count: 17
 Started worker count: 18
 Started worker count: 19
 Started worker count: 20
-Started worker count: 21
-Started worker count: 22
-Started worker count: 23
-Started worker count: 24
-Started worker count: 25
-Started worker count: 26
-Started worker count: 27
-Started worker count: 28
-Started worker count: 29
-Started worker count: 30
 Running operation.
 Closed worker count: 1
 Closed worker count: 2
@@ -54,15 +44,5 @@ Closed worker count: 17
 Closed worker count: 18
 Closed worker count: 19
 Closed worker count: 20
-Closed worker count: 21
-Closed worker count: 22
-Closed worker count: 23
-Closed worker count: 24
-Closed worker count: 25
-Closed worker count: 26
-Closed worker count: 27
-Closed worker count: 28
-Closed worker count: 29
-Closed worker count: 30
 DONE
 

third_party/WebKit/LayoutTests/http/tests/workers/terminate-during-sync-operation-filesystem-expected.txt

@@ -23,16 +23,6 @@ Started worker count: 17
 Started worker count: 18
 Started worker count: 19
 Started worker count: 20
-Started worker count: 21
-Started worker count: 22
-Started worker count: 23
-Started worker count: 24
-Started worker count: 25
-Started worker count: 26
-Started worker count: 27
-Started worker count: 28
-Started worker count: 29
-Started worker count: 30
 Running operation.
 Closed worker count: 1
 Closed worker count: 2
@@ -54,15 +44,5 @@ Closed worker count: 17
 Closed worker count: 18
 Closed worker count: 19
 Closed worker count: 20
-Closed worker count: 21
-Closed worker count: 22
-Closed worker count: 23
-Closed worker count: 24
-Closed worker count: 25
-Closed worker count: 26
-Closed worker count: 27
-Closed worker count: 28
-Closed worker count: 29
-Closed worker count: 30
 DONE