Don't expose native mixed radios as ax mixed

Do not expose native radio mixed state as accessibility mixed state, because
this confuses the JAWS screen reader, which reports a mixed radio as
both checked and partially checked. A native mixed native radio
button sinply means no radio buttons have been checked in the group yet.

Bug: 739752
Change-Id: Icdfc404b6d50d1ecb25b5b3221c79ba0da2f7400
Reviewed-on: https://chromium-review.googlesource.com/561817
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#484990}

content/test/data/accessibility/aria/aria-posinset-expected-blink.txt

@@ -6,20 +6,20 @@ rootWebArea
 ++++listBoxOption selectable name='Item 1' setSize=2 posInSet=1
 ++++listBoxOption selectable name='Item 2' setSize=2 posInSet=2
 ++form
-++++radioButton setSize=4 posInSet=3 checkedState=3
+++++radioButton setSize=4 posInSet=3 checkedState=1
 ++++staticText name='1'
 ++++++inlineTextBox name='1'
 ++++lineBreak name='<newline>'
 ++++++inlineTextBox name='<newline>'
-++++radioButton setSize=4 posInSet=4 checkedState=3
+++++radioButton setSize=4 posInSet=4 checkedState=1
 ++++staticText name='2'
 ++++++inlineTextBox name='2'
-++radioButton setSize=2 posInSet=1 checkedState=3
+++radioButton setSize=2 posInSet=1 checkedState=1
 ++staticText name='Apple'
 ++++inlineTextBox name='Apple'
 ++lineBreak name='<newline>'
 ++++inlineTextBox name='<newline>'
-++radioButton setSize=2 posInSet=2 checkedState=3
+++radioButton setSize=2 posInSet=2 checkedState=1
 ++staticText name='Banana'
 ++++inlineTextBox name='Banana'
 ++group name='Cake'
@@ -38,6 +38,6 @@ rootWebArea
 ++++++++++inlineTextBox name='red'
 ++++++lineBreak name='<newline>'
 ++++++++inlineTextBox name='<newline>'
-++++++radioButton name='blue' setSize=1 posInSet=1 checkedState=3
+++++++radioButton name='blue' setSize=1 posInSet=1 checkedState=1
 ++staticText name='Done'
 ++++inlineTextBox name='Done'

content/test/data/accessibility/aria/aria-posinset-expected-mac.txt

@@ -6,15 +6,15 @@ AXWebArea AXRoleDescription='HTML content'
 ++++AXStaticText AXRoleDescription='text' AXValue='Item 1' AXARIASetSize='2' AXARIAPosInSet='1'
 ++++AXStaticText AXRoleDescription='text' AXValue='Item 2' AXARIASetSize='2' AXARIAPosInSet='2'
 ++AXGroup AXRoleDescription='form'
-++++AXRadioButton AXRoleDescription='radio button' AXValue='2' AXARIASetSize='4' AXARIAPosInSet='3'
+++++AXRadioButton AXRoleDescription='radio button' AXValue='0' AXARIASetSize='4' AXARIAPosInSet='3'
 ++++AXStaticText AXRoleDescription='text' AXValue='1'
 ++++AXUnknown AXRoleDescription='unknown' AXTitle='<newline>'
-++++AXRadioButton AXRoleDescription='radio button' AXValue='2' AXARIASetSize='4' AXARIAPosInSet='4'
+++++AXRadioButton AXRoleDescription='radio button' AXValue='0' AXARIASetSize='4' AXARIAPosInSet='4'
 ++++AXStaticText AXRoleDescription='text' AXValue='2'
-++AXRadioButton AXRoleDescription='radio button' AXValue='2' AXARIASetSize='2' AXARIAPosInSet='1'
+++AXRadioButton AXRoleDescription='radio button' AXValue='0' AXARIASetSize='2' AXARIAPosInSet='1'
 ++AXStaticText AXRoleDescription='text' AXValue='Apple'
 ++AXUnknown AXRoleDescription='unknown' AXTitle='<newline>'
-++AXRadioButton AXRoleDescription='radio button' AXValue='2' AXARIASetSize='2' AXARIAPosInSet='2'
+++AXRadioButton AXRoleDescription='radio button' AXValue='0' AXARIASetSize='2' AXARIAPosInSet='2'
 ++AXStaticText AXRoleDescription='text' AXValue='Banana'
 ++AXGroup AXRoleDescription='group' AXTitle='Cake'
 ++++AXGroup AXRoleDescription='group'
@@ -28,5 +28,5 @@ AXWebArea AXRoleDescription='HTML content'
 ++++++AXGroup AXRoleDescription='group'
 ++++++++AXStaticText AXRoleDescription='text' AXValue='red'
 ++++++AXUnknown AXRoleDescription='unknown' AXTitle='<newline>'
-++++++AXRadioButton AXRoleDescription='radio button' AXTitle='blue' AXValue='2' AXARIASetSize='1' AXARIAPosInSet='1'
+++++++AXRadioButton AXRoleDescription='radio button' AXTitle='blue' AXValue='0' AXARIASetSize='1' AXARIAPosInSet='1'
 ++AXStaticText AXRoleDescription='text' AXValue='Done'

content/test/data/accessibility/aria/aria-posinset-expected-win.txt

@@ -6,15 +6,15 @@ ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE
 ++++ROLE_SYSTEM_LISTITEM name='Item 1' FOCUSABLE setsize:2 posinset:1
 ++++ROLE_SYSTEM_LISTITEM name='Item 2' FOCUSABLE setsize:2 posinset:2
 ++IA2_ROLE_FORM
-++++ROLE_SYSTEM_RADIOBUTTON MIXED FOCUSABLE IA2_STATE_CHECKABLE setsize:4 posinset:3 checkable:true
+++++ROLE_SYSTEM_RADIOBUTTON FOCUSABLE IA2_STATE_CHECKABLE setsize:4 posinset:3 checkable:true
 ++++ROLE_SYSTEM_STATICTEXT name='1'
 ++++ROLE_SYSTEM_WHITESPACE name='<newline>'
-++++ROLE_SYSTEM_RADIOBUTTON MIXED FOCUSABLE IA2_STATE_CHECKABLE setsize:4 posinset:4 checkable:true
+++++ROLE_SYSTEM_RADIOBUTTON FOCUSABLE IA2_STATE_CHECKABLE setsize:4 posinset:4 checkable:true
 ++++ROLE_SYSTEM_STATICTEXT name='2'
-++ROLE_SYSTEM_RADIOBUTTON MIXED FOCUSABLE IA2_STATE_CHECKABLE setsize:2 posinset:1 checkable:true
+++ROLE_SYSTEM_RADIOBUTTON FOCUSABLE IA2_STATE_CHECKABLE setsize:2 posinset:1 checkable:true
 ++ROLE_SYSTEM_STATICTEXT name='Apple'
 ++ROLE_SYSTEM_WHITESPACE name='<newline>'
-++ROLE_SYSTEM_RADIOBUTTON MIXED FOCUSABLE IA2_STATE_CHECKABLE setsize:2 posinset:2 checkable:true
+++ROLE_SYSTEM_RADIOBUTTON FOCUSABLE IA2_STATE_CHECKABLE setsize:2 posinset:2 checkable:true
 ++ROLE_SYSTEM_STATICTEXT name='Banana'
 ++ROLE_SYSTEM_GROUPING name='Cake'
 ++++IA2_ROLE_LABEL
@@ -28,5 +28,5 @@ ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE
 ++++++IA2_ROLE_LABEL
 ++++++++ROLE_SYSTEM_STATICTEXT name='red'
 ++++++ROLE_SYSTEM_WHITESPACE name='<newline>'
-++++++ROLE_SYSTEM_RADIOBUTTON name='blue' MIXED FOCUSABLE IA2_STATE_CHECKABLE setsize:1 posinset:1 checkable:true
+++++++ROLE_SYSTEM_RADIOBUTTON name='blue' FOCUSABLE IA2_STATE_CHECKABLE setsize:1 posinset:1 checkable:true
 ++ROLE_SYSTEM_STATICTEXT name='Done'
\ No newline at end of file

content/test/data/accessibility/html/action-verbs-expected-blink.txt

@@ -12,7 +12,7 @@ rootWebArea name='Action verbs'
 ++textField
 ++checkBox defaultActionVerb=2 checkedState=1
 ++checkBox defaultActionVerb=8 checkedState=2
-++radioButton defaultActionVerb=7 checkedState=3
+++radioButton defaultActionVerb=7 checkedState=1
 ++switch name='ARIA Switch' defaultActionVerb=2 checkedState=1
 ++popUpButton collapsed haspopup defaultActionVerb=5
 ++++menuListPopup invisible activedescendantId=menuListOption

content/test/data/accessibility/html/input-radio-expected-blink.txt

 rootWebArea
 ++form
-++++radioButton checkedState=3 radioGroupIds=radioButton
+++++radioButton checkedState=1 radioGroupIds=radioButton
 ++++staticText name='Radio1'
 ++++++inlineTextBox name='Radio1'
 ++++lineBreak name='<newline>'
 ++++++inlineTextBox name='<newline>'
-++++radioButton checkedState=3 radioGroupIds=radioButton
+++++radioButton checkedState=1 radioGroupIds=radioButton
 ++++staticText name='Radio2'
 ++++++inlineTextBox name='Radio2'
 ++form
 ++++radioButton name='Radio3' checkedState=1 radioGroupIds=radioButton,radioButton
 ++++radioButton name='Radio4' checkedState=2 radioGroupIds=radioButton,radioButton
 ++form
-++++radioButton name='Radio5' checkedState=3 radioGroupIds=radioButton
+++++radioButton name='Radio5' checkedState=1 radioGroupIds=radioButton
 ++++radioButton name='Radio6' checkedState=2 radioGroupIds=radioButton
\ No newline at end of file

content/test/data/accessibility/html/input-radio-expected-mac.txt

 AXWebArea
 ++AXGroup
-++++AXRadioButton AXValue='2' AXLinkedUIElements=["AXRadioButton 2"]
+++++AXRadioButton AXValue='0' AXLinkedUIElements=["AXRadioButton 0"]
 ++++AXStaticText AXValue='Radio1'
 ++++AXUnknown AXTitle='<newline>'
-++++AXRadioButton AXValue='2' AXLinkedUIElements=["AXRadioButton 2"]
+++++AXRadioButton AXValue='0' AXLinkedUIElements=["AXRadioButton 0"]
 ++++AXStaticText AXValue='Radio2'
 ++AXGroup
 ++++AXRadioButton AXTitle='Radio3' AXValue='0' AXLinkedUIElements=["AXRadioButton Radio3","AXRadioButton Radio4"]
 ++++AXRadioButton AXTitle='Radio4' AXValue='1' AXLinkedUIElements=["AXRadioButton Radio3","AXRadioButton Radio4"]
 ++AXGroup
-++++AXRadioButton AXTitle='Radio5' AXValue='2' AXLinkedUIElements=["AXRadioButton Radio5"]
+++++AXRadioButton AXTitle='Radio5' AXValue='0' AXLinkedUIElements=["AXRadioButton Radio5"]
 ++++AXRadioButton AXTitle='Radio6' AXValue='1' AXLinkedUIElements=["AXRadioButton Radio6"]
\ No newline at end of file

content/test/data/accessibility/html/input-radio-expected-win.txt

 ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE ia2_hypertext='<obj0><obj1><obj2>'
 ++IA2_ROLE_FORM ia2_hypertext='<obj0>Radio1<newline><obj3>Radio2'
-++++ROLE_SYSTEM_RADIOBUTTON MIXED FOCUSABLE IA2_STATE_CHECKABLE checkable:true
+++++ROLE_SYSTEM_RADIOBUTTON FOCUSABLE IA2_STATE_CHECKABLE checkable:true
 ++++ROLE_SYSTEM_STATICTEXT name='Radio1' ia2_hypertext='Radio1'
 ++++ROLE_SYSTEM_WHITESPACE name='<newline>' ia2_hypertext='<newline>'
-++++ROLE_SYSTEM_RADIOBUTTON MIXED FOCUSABLE IA2_STATE_CHECKABLE checkable:true
+++++ROLE_SYSTEM_RADIOBUTTON FOCUSABLE IA2_STATE_CHECKABLE checkable:true
 ++++ROLE_SYSTEM_STATICTEXT name='Radio2' ia2_hypertext='Radio2'
 ++IA2_ROLE_FORM ia2_hypertext='<obj0><obj1>'
 ++++ROLE_SYSTEM_RADIOBUTTON name='Radio3' FOCUSABLE IA2_STATE_CHECKABLE checkable:true ia2_hypertext='Radio3'
 ++++ROLE_SYSTEM_RADIOBUTTON name='Radio4' CHECKED FOCUSABLE IA2_STATE_CHECKABLE checkable:true ia2_hypertext='Radio4'
 ++IA2_ROLE_FORM ia2_hypertext='<obj0><obj1>'
-++++ROLE_SYSTEM_RADIOBUTTON name='Radio5' MIXED FOCUSABLE IA2_STATE_CHECKABLE checkable:true ia2_hypertext='Radio5'
+++++ROLE_SYSTEM_RADIOBUTTON name='Radio5' FOCUSABLE IA2_STATE_CHECKABLE checkable:true ia2_hypertext='Radio5'
 ++++ROLE_SYSTEM_RADIOBUTTON name='Radio6' CHECKED FOCUSABLE IA2_STATE_CHECKABLE checkable:true ia2_hypertext='Radio6'

third_party/WebKit/LayoutTests/accessibility/input-mixed.html

@@ -54,9 +54,9 @@
 
   test(function(t) {
     var ax = axElementById("element3");
-    assert_equals(ax.checked, "mixed");
+    assert_equals(ax.checked, "false");
   }, "A native radio that in a group with nothing checked" +
-      " must have the mixed state");
+      " must appear unchecked, not mixed");
 
   test(function(t) {
     var ax = axElementById("element4");

third_party/WebKit/Source/modules/accessibility/AXObject.cpp

@@ -539,7 +539,12 @@ AccessibilityCheckedState AXObject::CheckedState() const {
     if (!node)
       return kCheckedStateUndefined;
 
-    if (IsNativeInputInMixedState(node))
+    // Expose native checkbox mixed state as accessibility mixed state. However,
+    // do not expose native radio mixed state as accessibility mixed state.
+    // This would confuse the JAWS screen reader, which reports a mixed radio as
+    // both checked and partially checked, but a native mixed native radio
+    // button sinply means no radio buttons have been checked in the group yet.
+    if (IsNativeCheckboxInMixedState(node))
       return kCheckedStateMixed;
 
     if (isHTMLInputElement(*node) &&
@@ -551,14 +556,13 @@ AccessibilityCheckedState AXObject::CheckedState() const {
   return kCheckedStateFalse;
 }
 
-bool AXObject::IsNativeInputInMixedState(const Node* node) {
+bool AXObject::IsNativeCheckboxInMixedState(const Node* node) {
   if (!isHTMLInputElement(node))
     return false;
 
   const HTMLInputElement* input = toHTMLInputElement(node);
   const auto inputType = input->type();
-  if (inputType != InputTypeNames::checkbox &&
-      inputType != InputTypeNames::radio)
+  if (inputType != InputTypeNames::checkbox)
     return false;
   return input->ShouldAppearIndeterminate();
 }

third_party/WebKit/Source/modules/accessibility/AXObject.h

@@ -887,7 +887,7 @@ class MODULES_EXPORT AXObject : public GarbageCollectedFinalized<AXObject> {
 
  private:
   bool IsCheckable() const;
-  static bool IsNativeInputInMixedState(const Node*);
+  static bool IsNativeCheckboxInMixedState(const Node*);
   static bool IncludesARIAWidgetRole(const String&);
   static bool HasInteractiveARIAAttribute(const Element&);