Do not send redundant selectionchange-events (decouple focus)

third_party/WebKit/Source/web/tests/WebFrameTest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 4219 matching lines @@
   webViewHelper.initializeAndLoad(
       m_baseURL + "iframe_clear_focused_node_test.html", true);
 
   // Clear the focused node.
   webViewHelper.webView()->clearFocusedElement();
 
   // Now retrieve the FocusedNode and test it should be null.
   EXPECT_EQ(0, webViewHelper.webView()->focusedElement());
 }
 
+class ChangedSelectionCounter : public FrameTestHelpers::TestWebFrameClient {
+ public:
+  ChangedSelectionCounter() : m_callCount(0) {}
+  void didChangeSelection(bool isSelectionEmpty) { m_callCount++; }

[yosin_UTC9, 2017/02/09 13:02:17]

nit: It is OK to use post-increment, but I prefer pre-increment as same as
iterator increment pattern.

+  int count() const { return m_callCount; }
+  void reset() { m_callCount = 0; }
+
+ private:
+  int m_callCount;
+};
+
+TEST_P(ParameterizedWebFrameTest, OneFocusChangeMeansOneSelectionChange) {
+  ChangedSelectionCounter counter;
+  FrameTestHelpers::WebViewHelper webViewHelper;
+  registerMockedHttpURLLoad("editable_elements.html");
+  webViewHelper.initializeAndLoad(m_baseURL + "editable_elements.html", true,
+                                  &counter);
+
+  WebLocalFrameImpl* frame = webViewHelper.webView()->mainFrameImpl();
+  Document* document = frame->frame()->document();
+
+  // Move to a text-field.
+  Element* firstField = document->getElementById("input1");
+  counter.reset();
+  firstField->focus();
+  EXPECT_EQ(1, counter.count());
+
+  // Move to another text-field.
+  Element* secondField = document->getElementById("input2");
+  counter.reset();
+  secondField->focus();
+  EXPECT_EQ(1, counter.count());
+
+  // Move to a number-field.
+  Element* numberField = document->getElementById("input3");
+  counter.reset();
+  numberField->focus();
+  EXPECT_EQ(1, counter.count());
+
+  // Move to an editable element.
+  Element* editableP = document->getElementById("p1");
+  counter.reset();
+  editableP->focus();
+  EXPECT_EQ(1, counter.count());
+}
+
 // Implementation of WebFrameClient that tracks the v8 contexts that are created
 // and destroyed for verification.
 class ContextLifetimeTestWebFrameClient
     : public FrameTestHelpers::TestWebFrameClient {
  public:
   struct Notification {
    public:
     Notification(WebLocalFrame* frame,
                  v8::Local<v8::Context> context,
                  int worldId)
@@ skipping 7120 matching lines @@
 
   EXPECT_TRUE(mainFrameClient.childClient().didCallFrameDetached());
   EXPECT_TRUE(mainFrameClient.childClient().didCallDidStopLoading());
   EXPECT_TRUE(mainFrameClient.childClient().didCallDidFinishDocumentLoad());
   EXPECT_TRUE(mainFrameClient.childClient().didCallDidHandleOnloadEvents());
 
   webViewHelper.reset();
 }
 
 }  // namespace blink