Re-land: Fix loading accessibility tree for child frame that's already loaded.

content/browser/accessibility/dump_accessibility_tree_browsertest.cc

Index: content/browser/accessibility/dump_accessibility_tree_browsertest.cc
diff --git a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
index 0e4e6a81fc44e0d0491c565abbaeec8d9052c841..0aad741fe52ce6d41faaae9ccc75dc2e8228df5d 100644
--- a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
+++ b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
@@ -848,6 +848,12 @@ IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityFrameset) {
   RunHtmlTest(FILE_PATH_LITERAL("frameset.html"));
 }
 
+IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
+                       AccessibilityFramesetPostEnable) {
+  enable_accessibility_after_navigating_ = true;
+  RunHtmlTest(FILE_PATH_LITERAL("frameset.html"));
+}
+
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityHead) {
   RunHtmlTest(FILE_PATH_LITERAL("head.html"));
 }
@@ -882,6 +888,12 @@ IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityIframe) {
 }
 
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
+                       AccessibilityIframePostEnable) {
+  enable_accessibility_after_navigating_ = true;
+  RunHtmlTest(FILE_PATH_LITERAL("iframe.html"));
+}
+
+IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
                        AccessibilityIframeCrossProcess) {
   RunHtmlTest(FILE_PATH_LITERAL("iframe-cross-process.html"));
 }