Workaround PDF viewer brokenness when created in portal contents

A portal WebContents has TabHelpers even when embedded. When the helpers
are added, the portal WebContents is assigned a distinct tab ID. This is
an issue when attempting to load the PDF viewer as
ExtensionTabUtil::GetTabById cannot find the specified tab ID in the
TabStripModel.

Until we have a more thorough plan to deal with issue 1042323, we have
the PDF viewer load without a tab id when created in a portal.

Bug: 932691
Change-Id: Idbde43efcc1c0453abcea9b507cf01e9ef81f5f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2033325Reviewed-by: Lucas Gadani <lfg@chromium.org>
Reviewed-by: Zachary Kuznia <zork@chromium.org>
Commit-Queue: Kevin McNee <mcnee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737854}

chrome/browser/extensions/api/streams_private/streams_private_api.cc

@@ -8,6 +8,7 @@
 
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/prerender/prerender_contents.h"
+#include "components/sessions/core/session_id.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
@@ -66,7 +67,19 @@ void StreamsPrivateAPI::SendExecuteMimeTypeHandlerEvent(
   // will take ownership of the stream.
   GURL handler_url(Extension::GetBaseURLFromExtensionId(extension_id).spec() +
                    handler->handler_url());
-  int tab_id = ExtensionTabUtil::GetTabId(web_contents);
+
+  // If this is an inner contents, then (a) it's a guest view and doesn't have a
+  // tab id anyway, or (b) it's a portal. In the portal case, providing a
+  // distinct tab id breaks the pdf viewer / extension APIs. For now we just
+  // indicate that a portal contents has no tab id. Unfortunately, this will
+  // still be broken in subtle ways once the portal is activated (e.g. some
+  // forms of zooming won't work).
+  // TODO(1042323): Present a coherent representation of a tab id for portal
+  // contents.
+  int tab_id = web_contents->GetOuterWebContents()
+                   ? SessionID::InvalidValue().id()
+                   : ExtensionTabUtil::GetTabId(web_contents);
+
   std::unique_ptr<StreamContainer> stream_container(
       new StreamContainer(tab_id, embedded, handler_url, extension_id,
                           std::move(transferrable_loader), original_url));

chrome/browser/portal/portal_browsertest.cc

@@ -9,6 +9,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/scoped_feature_list.h"
 #include "chrome/browser/devtools/devtools_window_testing.h"
+#include "chrome/browser/pdf/pdf_extension_test_util.h"
 #include "chrome/browser/task_manager/providers/task.h"
 #include "chrome/browser/task_manager/task_manager_browsertest_util.h"
 #include "chrome/browser/task_manager/task_manager_tester.h"
@@ -239,3 +240,26 @@ IN_PROC_BROWSER_TEST_F(PortalBrowserTest, TaskManagerOrderingOfDependentRows) {
       kNumTabs * kPortalsPerTab, expected_portal_title);
   EXPECT_THAT(GetRendererTaskTitles(tester.get()), expected_titles);
 }
+
+IN_PROC_BROWSER_TEST_F(PortalBrowserTest, PdfViewerLoadsInPortal) {
+  ASSERT_TRUE(embedded_test_server()->Start());
+  GURL url(embedded_test_server()->GetURL("/title1.html"));
+  ui_test_utils::NavigateToURL(browser(), url);
+  WebContents* contents = browser()->tab_strip_model()->GetActiveWebContents();
+
+  ASSERT_EQ(true,
+            content::EvalJs(contents,
+                            "new Promise((resolve) => {\n"
+                            "  let portal = document.createElement('portal');\n"
+                            "  portal.src = '/pdf/test.pdf';\n"
+                            "  portal.onload = () => { resolve(true); }\n"
+                            "  document.body.appendChild(portal);\n"
+                            "});"));
+
+  std::vector<WebContents*> inner_web_contents =
+      contents->GetInnerWebContents();
+  ASSERT_EQ(1u, inner_web_contents.size());
+  WebContents* portal_contents = inner_web_contents[0];
+
+  EXPECT_TRUE(pdf_extension_test_util::EnsurePDFHasLoaded(portal_contents));
+}