Split TestRunner::setTopLoadingFrame into separate "set" and "clear" methods.

components/test_runner/test_runner.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/test_runner/test_runner.h"
 
 #include <stddef.h>
 #include <limits>
 #include <utility>
 
@@ skipping 1918 matching lines @@
 }
 
 bool TestRunner::shouldWaitUntilExternalURLLoad() const {
   return layout_test_runtime_flags_.wait_until_external_url_load();
 }
 
 const std::set<std::string>* TestRunner::httpHeadersToClear() const {
   return &http_headers_to_clear_;
 }
 
-void TestRunner::setTopLoadingFrame(WebFrame* frame, bool clear) {
-  if (frame->top()->view() != main_view_)
-    return;
-  if (!test_is_running_)
-    return;
-  if (clear) {
-    top_loading_frame_ = nullptr;
-    LocationChangeDone();
-  } else if (!top_loading_frame_) {
-    top_loading_frame_ = frame;
-  }
+bool TestRunner::IsFramePartOfMainTestWindow(blink::WebFrame* frame) const {
+  return test_is_running_ && frame->top()->view() == main_view_;
+}
+
+bool TestRunner::tryToSetTopLoadingFrame(WebFrame* frame) {
+  if (!IsFramePartOfMainTestWindow(frame))
+    return false;
+
+  if (top_loading_frame_)
+    return false;
+
+  top_loading_frame_ = frame;
+  return true;
+}
+
+bool TestRunner::tryToClearTopLoadingFrame(WebFrame* frame) {
+  if (!IsFramePartOfMainTestWindow(frame))
+    return false;
+
+  if (frame != top_loading_frame_)
+    return false;
+
+  top_loading_frame_ = nullptr;
+  LocationChangeDone();
+  return true;
 }
 
 WebFrame* TestRunner::topLoadingFrame() const {
   return top_loading_frame_;
 }
 
 void TestRunner::policyDelegateDone() {
   DCHECK(layout_test_runtime_flags_.wait_until_done());
   delegate_->TestFinished();
   layout_test_runtime_flags_.set_wait_until_done(false);
@@ skipping 1382 matching lines @@
 
 blink::WebView* TestRunnerForSpecificView::web_view() {
   return web_test_proxy_base_->web_view();
 }
 
 WebTestDelegate* TestRunnerForSpecificView::delegate() {
   return web_test_proxy_base_->delegate();
 }
 
 }  // namespace test_runner