Check script setting before invoking the mutation observer handler.

Bug: 848086 Change-Id: Icf22bbb2f3c82bdcb6ecdadf55967401630fe5fb Reviewed-on: https://chromium-review.googlesource.com/1085896Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org> Reviewed-by: Pavel Feldman <pfeldman@chromium.org> Commit-Queue: Johnny Ding <jnd@chromium.org> Cr-Commit-Position: refs/heads/master@{#564302}

Check script setting before invoking the mutation observer handler.
Bug: 848086 Change-Id: Icf22bbb2f3c82bdcb6ecdadf55967401630fe5fb Reviewed-on: https://chromium-review.googlesource.com/1085896Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org> Reviewed-by: Pavel Feldman <pfeldman@chromium.org> Commit-Queue: Johnny Ding <jnd@chromium.org> Cr-Commit-Position: refs/heads/master@{#564302}
e7c12ca3 · Johnny(Jianning) Ding · Commit Bot · 99fa9000 · e7c12ca3 · e7c12ca3
Commit e7c12ca3 authored Jun 05, 2018 by Johnny(Jianning) Ding Committed by Commit Bot Jun 05, 2018
3 changed files
--- a/third_party/WebKit/LayoutTests/inspector-protocol/page/not-invoke-mutation-observer-after-script-disabled-expected.txt
+++ b/third_party/WebKit/LayoutTests/inspector-protocol/page/not-invoke-mutation-observer-after-script-disabled-expected.txt
+Tests mutation observer invocation.
+Count: 2.
+Count: 2.
--- a/third_party/WebKit/LayoutTests/inspector-protocol/page/not-invoke-mutation-observer-after-script-disabled.js
+++ b/third_party/WebKit/LayoutTests/inspector-protocol/page/not-invoke-mutation-observer-after-script-disabled.js
+(async function(testRunner) {
+  var {page, session, dp} =
+      await testRunner.startHTML(`
+    <body><script>
+      count = 0;
+      var observer = new MutationObserver(() => {count++;});
+      observer.observe(document.body, {childList: true});
+    </script></body>
+`, 'Tests mutation observer invocation.');
+  async function triggerMutation() {
+    await session.evaluate(`document.body.appendChild(document.createTextNode('ha'))`);
+    let result = await session.evaluate(`count`);
+    testRunner.log(`Count: ${result}.`);
+  }
+  await triggerMutation();
+  await dp.Emulation.setScriptExecutionDisabled({value: true});
+  await triggerMutation();
+  testRunner.completeTest();
+})
--- a/third_party/blink/renderer/core/dom/mutation_observer.cc
+++ b/third_party/blink/renderer/core/dom/mutation_observer.cc
@@ -35,6 +35,7 @@
 #include "third_party/blink/renderer/bindings/core/v8/exception_state.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_binding_for_core.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_mutation_callback.h"
+#include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/dom/mutation_observer_init.h"
 #include "third_party/blink/renderer/core/dom/mutation_observer_registration.h"
 #include "third_party/blink/renderer/core/dom/mutation_record.h"
@@ -285,8 +286,13 @@ HeapHashSet<Member<Node>> MutationObserver::GetObservedNodes() const {
 }
 bool MutationObserver::ShouldBeSuspended() const {
-  const ExecutionContext* execution_context = delegate_->GetExecutionContext();
+  ExecutionContext* execution_context = delegate_->GetExecutionContext();
-  return execution_context && execution_context->IsContextPaused();
+  if (!execution_context)
+    return false;
+  Document* document = ToDocument(execution_context);
+  DCHECK(document);
+  return !document->CanExecuteScripts(kAboutToExecuteScript) ||
+         execution_context->IsContextPaused();
 }
 void MutationObserver::CancelInspectorAsyncTasks() {