WebLayer: delete a tab if its first navigation is a download.

Bug: 1127518
Change-Id: I9639b5b047033ec92331a2dc5bb8541e4e08546c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2406667
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806717}

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/DownloadCallbackTest.java

@@ -18,15 +18,19 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import org.chromium.base.test.util.CallbackHelper;
 import org.chromium.content_public.browser.test.util.Criteria;
 import org.chromium.content_public.browser.test.util.CriteriaHelper;
 import org.chromium.content_public.browser.test.util.TestThreadUtils;
 import org.chromium.net.test.util.TestWebServer;
+import org.chromium.weblayer.Browser;
 import org.chromium.weblayer.Download;
 import org.chromium.weblayer.DownloadCallback;
 import org.chromium.weblayer.DownloadError;
 import org.chromium.weblayer.DownloadState;
 import org.chromium.weblayer.Profile;
+import org.chromium.weblayer.Tab;
+import org.chromium.weblayer.TabListCallback;
 import org.chromium.weblayer.WebLayer;
 import org.chromium.weblayer.shell.InstrumentationActivity;
 
@@ -179,6 +183,46 @@ public class DownloadCallbackTest {
         }
     }
 
+    /**
+     * Verifies that if the first navigation in a Tab is for a download then it is deleted.
+     */
+    @Test
+    @SmallTest
+    public void testFirstNavigationIsDownloadClosesTab() throws Throwable {
+        // Set up listening for the tab removal that we expect to happen.
+        CallbackHelper onTabRemovedCallbackHelper = new CallbackHelper();
+        TabListCallback tabListCallback = new TabListCallback() {
+            @Override
+            public void onTabRemoved(Tab tab) {
+                onTabRemovedCallbackHelper.notifyCalled();
+            }
+        };
+        Browser browser = mActivityTestRule.getActivity().getBrowser();
+        TestThreadUtils.runOnUiThreadBlocking(
+                () -> { browser.registerTabListCallback(tabListCallback); });
+
+        final String data = "download data";
+        final String contentDisposition = "attachment;filename=\"download.txt\"";
+        final String mimetype = "text/plain";
+
+        List<Pair<String, String>> downloadHeaders = new ArrayList<Pair<String, String>>();
+        downloadHeaders.add(Pair.create("Content-Disposition", contentDisposition));
+        downloadHeaders.add(Pair.create("Content-Type", mimetype));
+        downloadHeaders.add(Pair.create("Content-Length", Integer.toString(data.length())));
+
+        TestWebServer webServer = TestWebServer.start();
+        try {
+            final String pageUrl = webServer.setResponse("/download.txt", data, downloadHeaders);
+            TestThreadUtils.runOnUiThreadBlocking(() -> {
+                mActivity.getTab().getNavigationController().navigate(Uri.parse(pageUrl));
+            });
+            mCallback.waitForCompleted();
+            onTabRemovedCallbackHelper.waitForFirst();
+        } finally {
+            webServer.shutdown();
+        }
+    }
+
     /**
      * Verifies the DownloadCallback is informed of downloads resulting from the user clicking on a
      * download link.

weblayer/browser/download_browsertest.cc

@@ -281,6 +281,10 @@ IN_PROC_BROWSER_TEST_F(DownloadBrowserTest, Cancel) {
 }
 
 IN_PROC_BROWSER_TEST_F(DownloadBrowserTest, PauseResume) {
+  // Add an initial navigation to avoid the tab being deleted if the first
+  // navigation is a download, since we use the tab for convenience in the
+  // lambda.
+  shell()->tab()->GetNavigationController()->Navigate(GURL("about:blank"));
   set_started_callback(base::BindLambdaForTesting([&](Download* download) {
     download->Pause();
     GURL url = embedded_test_server()->GetURL(

weblayer/browser/download_manager_delegate_impl.cc

@@ -209,6 +209,16 @@ void DownloadManagerDelegateImpl::OnManagerInitialized() {
 
 void DownloadManagerDelegateImpl::OnDownloadUpdated(
     download::DownloadItem* item) {
+  // If this is the first navigation in a tab it should be closed. Wait until
+  // the target path is determined or the download is canceled to check.
+  if (!item->GetTargetFilePath().empty() ||
+      item->GetState() == download::DownloadItem::CANCELLED) {
+    content::WebContents* web_contents =
+        content::DownloadItemUtils::GetWebContents(item);
+    if (web_contents && web_contents->GetController().IsInitialNavigation())
+      web_contents->Close();
+  }
+
   auto* delegate = GetDelegate(item);
   if (item->GetState() == download::DownloadItem::COMPLETE ||
       item->GetState() == download::DownloadItem::CANCELLED ||

weblayer/shell/browser/shell.cc

@@ -103,7 +103,8 @@ void Shell::SetMainMessageLoopQuitClosure(base::OnceClosure quit_closure) {
 Tab* Shell::tab() {
   if (!browser())
     return nullptr;
-  CHECK(!browser()->GetTabs().empty());
+  if (browser()->GetTabs().empty())
+    return nullptr;
   return browser()->GetTabs()[0];
 }