ui: Cleanup class/struct forward declarations

content/browser/frame_host/frame_tree_browsertest.cc

Index: content/browser/frame_host/frame_tree_browsertest.cc
diff --git a/content/browser/frame_host/frame_tree_browsertest.cc b/content/browser/frame_host/frame_tree_browsertest.cc
index bc3078e158c82f8978ebeeb106f2459d5b0b2e01..f94b415ffa2499749f06df7650e1696c4c9655c1 100644
--- a/content/browser/frame_host/frame_tree_browsertest.cc
+++ b/content/browser/frame_host/frame_tree_browsertest.cc
@@ -323,6 +323,7 @@ IN_PROC_BROWSER_TEST_F(FrameTreeBrowserTest, NavigateGrandchildToBlob) {
   FrameTreeNode* target = root->child_at(0)->child_at(0);
 
   std::string blob_url_string;
+  RenderFrameDeletedObserver deleted_observer(target->current_frame_host());
   EXPECT_TRUE(ExecuteScriptAndExtractString(
       root,
       "function receiveMessage(event) {"
@@ -337,6 +338,9 @@ IN_PROC_BROWSER_TEST_F(FrameTreeBrowserTest, NavigateGrandchildToBlob) {
       "var blob_url = URL.createObjectURL(blob);"
       "frames[0][0].location.href = blob_url;",
       &blob_url_string));
+  // Wait for the RenderFrame to go away, if this will be cross-process.
+  if (AreAllSitesIsolatedForTesting())
+    deleted_observer.WaitUntilDeleted();
   EXPECT_EQ(GURL(blob_url_string), target->current_url());
   EXPECT_EQ(url::kBlobScheme, target->current_url().scheme());
   EXPECT_FALSE(target->current_origin().unique());