Reland: Fix crash when right clicking link in CastUI

This CL adds a null check to RenderViewContextMenu::AppendLinkItems()
ensuring we have an associated Browser before attempting to use it.

This is a reland of https://chromium-review.googlesource.com/c/chromium/src/+/1158110
without using TestWebContents (which results in a bad downcast).

Bug: 869280
Change-Id: I6799f0c746c0cdca941e1235ac476f4e1d8a1f0e
Reviewed-on: https://chromium-review.googlesource.com/1160121Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580405}

chrome/browser/renderer_context_menu/render_view_context_menu.cc

@@ -1032,13 +1032,16 @@ void RenderViewContextMenu::AppendDevtoolsForUnpackedExtensions() {
 void RenderViewContextMenu::AppendLinkItems() {
   if (!params_.link_url.is_empty()) {
     if (base::FeatureList::IsEnabled(features::kDesktopPWAWindowing)) {
+      const Browser* browser = GetBrowser();
+      const bool is_app = browser && browser->is_app();
+
       AppendOpenInBookmarkAppLinkItems();
 
       menu_model_.AddItemWithStringId(
           IDC_CONTENT_CONTEXT_OPENLINKNEWTAB,
-          GetBrowser()->is_app() ? IDS_CONTENT_CONTEXT_OPENLINKNEWTAB_INAPP
-                                 : IDS_CONTENT_CONTEXT_OPENLINKNEWTAB);
-      if (!GetBrowser()->is_app()) {
+          is_app ? IDS_CONTENT_CONTEXT_OPENLINKNEWTAB_INAPP
+                 : IDS_CONTENT_CONTEXT_OPENLINKNEWTAB);
+      if (!is_app) {
         menu_model_.AddItemWithStringId(IDC_CONTENT_CONTEXT_OPENLINKNEWWINDOW,
                                         IDS_CONTENT_CONTEXT_OPENLINKNEWWINDOW);
       }
@@ -1049,9 +1052,8 @@ void RenderViewContextMenu::AppendLinkItems() {
 
       menu_model_.AddItemWithStringId(
           IDC_CONTENT_CONTEXT_OPENLINKOFFTHERECORD,
-          GetBrowser()->is_app()
-              ? IDS_CONTENT_CONTEXT_OPENLINKOFFTHERECORD_INAPP
-              : IDS_CONTENT_CONTEXT_OPENLINKOFFTHERECORD);
+          is_app ? IDS_CONTENT_CONTEXT_OPENLINKOFFTHERECORD_INAPP
+                 : IDS_CONTENT_CONTEXT_OPENLINKOFFTHERECORD);
 
     } else {
       menu_model_.AddItemWithStringId(IDC_CONTENT_CONTEXT_OPENLINKNEWTAB,
@@ -1193,8 +1195,10 @@ void RenderViewContextMenu::AppendOpenInBookmarkAppLinkItems() {
     return;
 
   int open_in_app_string_id;
-  if (GetBrowser()->app_name() ==
-      web_app::GenerateApplicationNameFromExtensionId(pwa->id())) {
+  const Browser* browser = GetBrowser();
+  if (browser &&
+      browser->app_name() ==
+          web_app::GenerateApplicationNameFromExtensionId(pwa->id())) {
     open_in_app_string_id = IDS_CONTENT_CONTEXT_OPENLINKBOOKMARKAPP_SAMEAPP;
   } else {
     open_in_app_string_id = IDS_CONTENT_CONTEXT_OPENLINKBOOKMARKAPP;

chrome/browser/renderer_context_menu/render_view_context_menu.h

@@ -81,6 +81,8 @@ class RenderViewContextMenu : public RenderViewContextMenuBase {
 
  protected:
   Profile* GetProfile() const;
+
+  // This may return nullptr (e.g. for WebUI dialogs).
   Browser* GetBrowser() const;
 
   // Returns a (possibly truncated) version of the current selection text

chrome/browser/renderer_context_menu/render_view_context_menu_browsertest.cc

@@ -1244,4 +1244,18 @@ IN_PROC_BROWSER_TEST_F(ContextMenuBrowserTest,
   EXPECT_TRUE(menu.IsItemChecked(IDC_CONTENT_CONTEXT_PICTUREINPICTURE));
 }
 
+// This test checks that we don't crash when creating a context menu for a
+// WebContents with no Browser.
+IN_PROC_BROWSER_TEST_F(ContextMenuBrowserTest, BrowserlessWebContentsCrash) {
+  base::test::ScopedFeatureList feature_list;
+  feature_list.InitAndEnableFeature(features::kDesktopPWAWindowing);
+  std::unique_ptr<content::WebContents> web_contents =
+      content::WebContents::Create(
+          content::WebContents::CreateParams(browser()->profile()));
+  CreateContextMenuInWebContents(
+      web_contents.get(), GURL("http://www.google.com/"),
+      GURL("http://www.google.com/"), base::ASCIIToUTF16("Google"),
+      blink::WebContextMenuData::kMediaTypeNone, ui::MENU_SOURCE_MOUSE);
+}
+
 }  // namespace