Fix flakiness in DumpAccessibilityTree tests with iframes

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 560027b37769288b3e6a9845e4f29b37065956d7..bfbb90dd8018a87d284be1ed7146441c65db232f 100644
--- a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
+++ b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
@@ -886,15 +886,13 @@ IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
   RunHtmlTest(FILE_PATH_LITERAL("iframe-cross-process.html"));
 }
 
-// Flaky on all platforms: https://crbug.com/622387
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
-                       DISABLED_AccessibilityIframeCoordinates) {
+                       AccessibilityIframeCoordinates) {
   RunHtmlTest(FILE_PATH_LITERAL("iframe-coordinates.html"));
 }
 
-// Flaky on all platforms: https://crbug.com/622387
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
-                       DISABLED_AccessibilityIframeCoordinatesCrossProcess) {
+                       AccessibilityIframeCoordinatesCrossProcess) {
   RunHtmlTest(FILE_PATH_LITERAL("iframe-coordinates-cross-process.html"));
 }
 
@@ -909,15 +907,13 @@ IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
   RunHtmlTest(FILE_PATH_LITERAL("iframe-presentational.html"));
 }
 
-// Flaky on all platforms: https://crbug.com/622387
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
-                       DISABLED_AccessibilityIframeTransform) {
+                       AccessibilityIframeTransform) {
   RunHtmlTest(FILE_PATH_LITERAL("iframe-transform.html"));
 }
 
-// Flaky on all platforms: https://crbug.com/622387
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
-                       DISABLED_AccessibilityIframeTransformCrossProcess) {
+                       AccessibilityIframeTransformCrossProcess) {
   RunHtmlTest(FILE_PATH_LITERAL("iframe-transform-cross-process.html"));
 }