Revert "Reapply "Headless: don't run unload hooks upon web contents close.""

This reverts commit dc9251bd.

Reason for revert: headless_browsertests are flaky on Win7:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Win7%20Tests%20%28dbg%29%281%29. This looks like the only possible culprit.

Original change's description:
> Reapply "Headless: don't run unload hooks upon web contents close."
> 
> Change-Id: Ic98de1070c3cee34a926ee0a95eb05cd62345ce6
> Reviewed-on: https://chromium-review.googlesource.com/1113309
> Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
> Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#570003}

TBR=caseq@chromium.org,pfeldman@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Idb3d74d77c445ee6e870ca3bf476e8a34374b0f9
Reviewed-on: https://chromium-review.googlesource.com/1115839Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570588}

headless/lib/browser/headless_web_contents_impl.cc

@@ -95,7 +95,7 @@ class HeadlessWebContentsImpl::Delegate : public content::WebContentsDelegate {
     auto* const headless_contents =
         HeadlessWebContentsImpl::From(browser(), source);
     DCHECK(headless_contents);
-    headless_contents->Close();
+    headless_contents->DelegateRequestsClose();
   }
 
   void AddNewContents(content::WebContents* source,
@@ -379,9 +379,29 @@ bool HeadlessWebContentsImpl::OpenURL(const GURL& url) {
 
 void HeadlessWebContentsImpl::Close() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (quit_closure_)
+    return;
+
+  if (!render_process_exited_) {
+    web_contents_->ClosePage();
+    base::RunLoop run_loop(base::RunLoop::Type::kNestableTasksAllowed);
+    quit_closure_ = run_loop.QuitClosure();
+    run_loop.Run();
+  }
+
   browser_context()->DestroyWebContents(this);
 }
 
+void HeadlessWebContentsImpl::DelegateRequestsClose() {
+  if (quit_closure_) {
+    quit_closure_.Run();
+    quit_closure_ = base::Closure();
+  } else {
+    browser_context()->DestroyWebContents(this);
+  }
+}
+
 std::string HeadlessWebContentsImpl::GetDevToolsAgentHostId() {
   return agent_host_->GetId();
 }

headless/lib/browser/headless_web_contents_impl.h

@@ -99,6 +99,8 @@ class HEADLESS_EXPORT HeadlessWebContentsImpl
 
   void Close() override;
 
+  void DelegateRequestsClose();
+
   std::string GetDevToolsAgentHostId();
 
   HeadlessBrowserImpl* browser() const;
@@ -176,6 +178,8 @@ class HEADLESS_EXPORT HeadlessWebContentsImpl
 
   base::ObserverList<HeadlessWebContents::Observer> observers_;
 
+  base::Closure quit_closure_;
+
   base::WeakPtrFactory<HeadlessWebContentsImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HeadlessWebContentsImpl);

headless/lib/headless_devtools_client_browsertest.cc

@@ -456,6 +456,84 @@ class TargetDomainCreateAndDeletePageTest
 
 HEADLESS_ASYNC_DEVTOOLED_TEST_F(TargetDomainCreateAndDeletePageTest);
 
+class TargetDomainCreateAndDeleteBrowserContextTest
+    : public HeadlessAsyncDevTooledBrowserTest {
+  void RunDevTooledTest() override {
+    EXPECT_TRUE(embedded_test_server()->Start());
+
+    EXPECT_EQ(1u, GetAllWebContents(browser()).size());
+
+    devtools_client_->GetTarget()->GetExperimental()->CreateBrowserContext(
+        target::CreateBrowserContextParams::Builder().Build(),
+        base::BindOnce(&TargetDomainCreateAndDeleteBrowserContextTest::
+                           OnCreateContextResult,
+                       base::Unretained(this)));
+  }
+
+  void OnCreateContextResult(
+      std::unique_ptr<target::CreateBrowserContextResult> result) {
+    browser_context_id_ = result->GetBrowserContextId();
+
+    devtools_client_->GetTarget()->GetExperimental()->CreateTarget(
+        target::CreateTargetParams::Builder()
+            .SetUrl(embedded_test_server()->GetURL("/hello.html").spec())
+            .SetBrowserContextId(result->GetBrowserContextId())
+            .SetWidth(1)
+            .SetHeight(1)
+            .Build(),
+        base::BindOnce(&TargetDomainCreateAndDeleteBrowserContextTest::
+                           OnCreateTargetResult,
+                       base::Unretained(this)));
+  }
+
+  void OnCreateTargetResult(
+      std::unique_ptr<target::CreateTargetResult> result) {
+    EXPECT_EQ(2u, GetAllWebContents(browser()).size());
+
+    devtools_client_->GetTarget()->GetExperimental()->CloseTarget(
+        target::CloseTargetParams::Builder()
+            .SetTargetId(result->GetTargetId())
+            .Build(),
+        base::BindOnce(
+            &TargetDomainCreateAndDeleteBrowserContextTest::OnCloseTargetResult,
+            base::Unretained(this)));
+  }
+
+  void OnCloseTargetResult(std::unique_ptr<target::CloseTargetResult> result) {
+    EXPECT_EQ(1u, GetAllWebContents(browser()).size());
+    EXPECT_TRUE(result->GetSuccess());
+
+    devtools_client_->GetTarget()->GetExperimental()->DisposeBrowserContext(
+        target::DisposeBrowserContextParams::Builder()
+            .SetBrowserContextId(browser_context_id_)
+            .Build(),
+        base::BindOnce(&TargetDomainCreateAndDeleteBrowserContextTest::
+                           OnDisposeBrowserContextResult,
+                       base::Unretained(this)));
+  }
+
+  void OnDisposeBrowserContextResult(
+      std::unique_ptr<target::DisposeBrowserContextResult> result) {
+    devtools_client_->GetTarget()->GetExperimental()->GetBrowserContexts(
+        target::GetBrowserContextsParams::Builder().Build(),
+        base::BindOnce(&TargetDomainCreateAndDeleteBrowserContextTest::
+                           OnGetBrowserContexts,
+                       base::Unretained(this)));
+  }
+
+  void OnGetBrowserContexts(
+      std::unique_ptr<target::GetBrowserContextsResult> result) {
+    const std::vector<std::string>* contexts = result->GetBrowserContextIds();
+    EXPECT_EQ(0u, contexts->size());
+    FinishAsynchronousTest();
+  }
+
+ private:
+  std::string browser_context_id_;
+};
+
+HEADLESS_ASYNC_DEVTOOLED_TEST_F(TargetDomainCreateAndDeleteBrowserContextTest);
+
 class TargetDomainDisposeContextSucceedsIfInUse
     : public target::Observer,
       public HeadlessAsyncDevTooledBrowserTest {