Revert "A11y:Expose labels of radio & checkbox when focused."

This reverts commit 9612f58a.

Reason for revert: breaking linux-trusty-rel bot. Sample failure:
https://ci.chromium.org/p/chromium/builders/ci/linux-trusty-rel/6828
https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8891225736395206976/+/steps/content_browsertests_on_Ubuntu-14.04/0/logs/Deterministic_failure:_All__x2f_DumpAccessibilityTreeTest.AccessibilityInputRadioCheckboxLabel__x2f_linux__status_FAILURE_/0

[18791:18791:0114/205350.062302:INFO:dump_accessibility_test_helper.cc(98)] Expected output: /b/s/w/ir/content/test/data/accessibility/html/input-radio-checkbox-label-expected-auralinux.txt
[18791:18791:0114/205350.062327:ERROR:dump_accessibility_test_helper.cc(126)] Diff:
* Line Expected
- ---- --------
     1 [document web]
     2 ++[section]
*    3 ++++[radio button] name='label ignored for radio button' checkable checkable:true
*    4 ++++[check box] name='label ignored for checkbox' checkable checkable:true
     5 ++++[label] name='label exposed for radio button ' label-for
     6 ++++++[static] name='label exposed for radio button '
*    7 ++++++[radio button] name='label exposed for radio button' checkable labelled-by checkable:true
     8 ++++++[static] name=' '
     9 ++++[label] name='label exposed for checkbox ' label-for
    10 ++++++[static] name='label exposed for checkbox '
*   11 ++++++[check box] name='label exposed for checkbox' checkable labelled-by checkable:true
    12 ++++++[static] name=' '
    13 <-- End-of-file -->

Actual
------
[document web]
++[section]
++++[radio button] name='label ignored for radio button' checkable:true
++++[check box] name='label ignored for checkbox' checkable:true
++++[label] name='label exposed for radio button ' label-for
++++++[static] name='label exposed for radio button '
++++++[radio button] name='label exposed for radio button' labelled-by checkable:true
++++++[static] name=' '
++++[label] name='label exposed for checkbox ' label-for
++++++[static] name='label exposed for checkbox '
++++++[check box] name='label exposed for checkbox' labelled-by checkable:true
++++++[static] name=' '
<-- End-of-file -->
../../content/browser/accessibility/dump_accessibility_browsertest_base.cc:442: Failure
Value of: matches_expectation
  Actual: false
Expected: true

Original change's description:
> A11y:Expose labels of radio & checkbox when focused.
> 
> Currently, when a label is referenced by a control of type radio or
> checkbox, we set the label as ignored in the AXTree thereby excluding
> it from being perceived by ATs.
> However, for the case when the control (radio/checkbox) is a
> descendant of the label and label is focusable (tabindex="0") but
> control is to be omitted from focus (tabindex="-1"), ATs perceive
> neither the label nor the control when tabbing through the content:
> 
>     <label style="display:block" tabindex="0">
>       radio button 1
>       <input type="radio" id="radio1" tabindex="-1">
>     </label>
> 
>     <label style="display:block" for="radio2" tabindex="0">
>       radio button 2
>       <input type="radio" id="radio2" tabindex="-1">
>     </label>
> 
>     <label style="display:block" for="checkbox1" tabindex="0">
>       checkbox 1
>       <input type="checkbox" id="checkbox1" tabindex="-1">
>     </label>
> 
>     <label style="display:block" for="checkbox2" tabindex="0">
>       checkbox 2
>       <input type="checkbox" id="checkbox2" tabindex="-1">
>     </label>
> 
> This change fixes the above scenario by exposing labels (referenced by
> radio or checkbox) when they are focusable. For all other cases when
> labels are referenced by radio or checkbox, we keep the existing
> behavior of ignoring the label.
> 
> Note: Neither Firefox nor Edge legacy hides a label from AT when the
> label is referenced by a control. On Firefox and Edge legacy, label
> content will be read twice (focus on label and focus on control
> respectively).
> WAI-ARIA spec does not specify label should be ignored when associated
> with a radio/checkbox control.
> 
> Bug: 1040210
> Change-Id: Ie7df5144dd2f0d285d97e6556adb46dcf2338f25
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1992017
> Commit-Queue: Victor Fei <vicfei@microsoft.com>
> Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#731820}

TBR=dmazzoni@chromium.org,chrishall@chromium.org,meredithl@chromium.org,kschmi@microsoft.com,iapres@microsoft.com,vicfei@microsoft.com

Change-Id: I288116c0ed48350e8a7104c8fb698b4f3214e97b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1040210
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000728Reviewed-by: Marina Ciocea <marinaciocea@chromium.org>
Commit-Queue: Marina Ciocea <marinaciocea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731886}

content/browser/accessibility/dump_accessibility_tree_browsertest.cc

@@ -1661,11 +1661,6 @@ IN_PROC_BROWSER_TEST_P(DumpAccessibilityTreeTest, AccessibilityInputRadio) {
   RunHtmlTest(FILE_PATH_LITERAL("input-radio.html"));
 }
 
-IN_PROC_BROWSER_TEST_P(DumpAccessibilityTreeTest,
-                       AccessibilityInputRadioCheckboxLabel) {
-  RunHtmlTest(FILE_PATH_LITERAL("input-radio-checkbox-label.html"));
-}
-
 IN_PROC_BROWSER_TEST_P(DumpAccessibilityTreeTest,
                        AccessibilityInputRadioInMenu) {
   RunHtmlTest(FILE_PATH_LITERAL("input-radio-in-menu.html"));

content/test/data/accessibility/html/input-radio-checkbox-label-expected-android.txt

-android.webkit.WebView focusable focused scrollable
-++android.view.View
-++++android.widget.RadioButton role_description='radio button' checkable clickable focusable name='label ignored for radio button'
-++++android.widget.CheckBox role_description='checkbox' checkable clickable focusable name='label ignored for checkbox'
-++++android.view.View focusable name='label exposed for radio button '
-++++++android.view.View name='label exposed for radio button '
-++++++android.widget.RadioButton role_description='radio button' checkable clickable focusable name='label exposed for radio button' item_index=1 row_index=1
-++++++android.view.View name=' '
-++++android.view.View focusable name='label exposed for checkbox '
-++++++android.view.View name='label exposed for checkbox '
-++++++android.widget.CheckBox role_description='checkbox' checkable clickable focusable name='label exposed for checkbox'
-++++++android.view.View name=' '

content/test/data/accessibility/html/input-radio-checkbox-label-expected-auralinux.txt

-[document web]
-++[section]
-++++[radio button] name='label ignored for radio button' checkable checkable:true
-++++[check box] name='label ignored for checkbox' checkable checkable:true
-++++[label] name='label exposed for radio button ' label-for
-++++++[static] name='label exposed for radio button '
-++++++[radio button] name='label exposed for radio button' checkable labelled-by checkable:true
-++++++[static] name=' '
-++++[label] name='label exposed for checkbox ' label-for
-++++++[static] name='label exposed for checkbox '
-++++++[check box] name='label exposed for checkbox' checkable labelled-by checkable:true
-++++++[static] name=' '

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

-rootWebArea
-++genericContainer
-++++radioButton name='label ignored for radio button' checkedState=false
-++++checkBox name='label ignored for checkbox' checkedState=false
-++++labelText name='label exposed for radio button '
-++++++staticText name='label exposed for radio button '
-++++++++inlineTextBox name='label exposed for radio button '
-++++++radioButton name='label exposed for radio button' checkedState=false
-++++++staticText name=' '
-++++++++inlineTextBox name=' '
-++++labelText name='label exposed for checkbox '
-++++++staticText name='label exposed for checkbox '
-++++++++inlineTextBox name='label exposed for '
-++++++++inlineTextBox name='checkbox '
-++++++checkBox name='label exposed for checkbox' checkedState=false
-++++++staticText name=' '

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

-AXWebArea
-++AXGroup
-++++AXRadioButton AXTitle='label ignored for radio button' AXValue='0'
-++++AXCheckBox AXTitle='label ignored for checkbox' AXValue='0'
-++++AXGroup AXTitle='label exposed for radio button '
-++++++AXStaticText AXValue='label exposed for radio button '
-++++++AXRadioButton AXValue='0' AXTitleUIElement='AXGroup label exposed for radio button '
-++++++AXStaticText AXValue=' '
-++++AXGroup AXTitle='label exposed for checkbox '
-++++++AXStaticText AXValue='label exposed for checkbox '
-++++++AXCheckBox AXValue='0' AXTitleUIElement='AXGroup label exposed for checkbox '
-++++++AXStaticText AXValue=' '

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

-document
-++group IsControlElement=false
-++++radio Name='label ignored for radio button' SelectionItem.IsSelected=false
-++++checkbox Name='label ignored for checkbox' Toggle.ToggleState='Off'
-++++description Name='label exposed for radio button '
-++++++description Name='label exposed for radio button '
-++++++radio Name='label exposed for radio button' SelectionItem.IsSelected=false
-++++++description Name=' '
-++++description Name='label exposed for checkbox '
-++++++description Name='label exposed for checkbox '
-++++++checkbox Name='label exposed for checkbox' Toggle.ToggleState='Off'
-++++++description Name=' '

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

-ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE
-++IA2_ROLE_SECTION
-++++ROLE_SYSTEM_RADIOBUTTON name='label ignored for radio button' FOCUSABLE IA2_STATE_CHECKABLE checkable:true
-++++ROLE_SYSTEM_CHECKBUTTON name='label ignored for checkbox' FOCUSABLE IA2_STATE_CHECKABLE checkable:true
-++++IA2_ROLE_LABEL name='label exposed for radio button ' FOCUSABLE
-++++++ROLE_SYSTEM_STATICTEXT name='label exposed for radio button '
-++++++ROLE_SYSTEM_RADIOBUTTON name='label exposed for radio button' FOCUSABLE IA2_STATE_CHECKABLE checkable:true
-++++++ROLE_SYSTEM_STATICTEXT name=' '
-++++IA2_ROLE_LABEL name='label exposed for checkbox ' FOCUSABLE
-++++++ROLE_SYSTEM_STATICTEXT name='label exposed for checkbox '
-++++++ROLE_SYSTEM_CHECKBUTTON name='label exposed for checkbox' FOCUSABLE IA2_STATE_CHECKABLE checkable:true
-++++++ROLE_SYSTEM_STATICTEXT name=' '

content/test/data/accessibility/html/input-radio-checkbox-label.html

-<!DOCTYPE html>
-<html>
-<body>
-  <body>
-    <!-- When the radio button's associated label is not set to be
-      focusable, it will be ignored from the accessibility tree. -->
-    <label for="radio1">
-      label ignored for radio button
-      <input type="radio" id="radio1">
-    </label>
-
-    <!-- When the checkbox's associated label is not set to be
-      focusable, it will be ignored from the accessibility tree. -->
-    <label for="checkbox1">
-      label ignored for checkbox
-      <input type="checkbox" id="checkbox1">
-    </label>
-
-    <!-- When the radio button's associated label is set to be focusable,
-      it will be included in the accessibility tree. -->
-    <label for="radio2" tabindex="0">
-      label exposed for radio button
-      <input type="radio" id="radio2" tabindex="-1">
-    </label>
-
-    <!-- When the checkbox's associated label is set to be focusable,
-      it will be included in the accessibility tree. -->
-    <label for="checkbox2" tabindex="0">
-      label exposed for checkbox
-      <input type="checkbox" id="checkbox2" tabindex="-1">
-    </label>
-  </body>
-</html>

third_party/blink/renderer/modules/accessibility/ax_layout_object.cc

@@ -1742,8 +1742,7 @@ AXObject* AXLayoutObject::AccessibilityHitTest(const IntPoint& point) const {
     // control.
     if (result->IsAXLayoutObject()) {
       AXObject* control_object =
-          ToAXLayoutObject(result)
-              ->CorrespondingControlAXObjectForLabelElement();
+          ToAXLayoutObject(result)->CorrespondingControlForLabelElement();
       if (control_object && control_object->NameFromLabelElement())
         return control_object;
     }

third_party/blink/renderer/modules/accessibility/ax_node_object.cc

@@ -178,24 +178,21 @@ AXObjectInclusion AXNodeObject::ShouldIncludeBasedOnSemantics(
   if (IsTableLikeRole() || IsTableRowLikeRole() || IsTableCellLikeRole())
     return kIncludeObject;
 
-  // Ignore labels that are already referenced by a control but are not set to
-  // be focusable.
-  AXObject* control_ax_object = CorrespondingControlAXObjectForLabelElement();
-  if (control_ax_object && control_ax_object->IsCheckboxOrRadio() &&
-      control_ax_object->NameFromLabelElement() &&
+  // Ignore labels that are already referenced by a control.
+  AXObject* control_object = CorrespondingControlForLabelElement();
+  HTMLLabelElement* label = LabelElementContainer();
+  if (control_object && control_object->IsCheckboxOrRadio() &&
+      control_object->NameFromLabelElement() &&
       AccessibleNode::GetPropertyOrARIAAttribute(
-          LabelElementContainer(), AOMStringProperty::kRole) == g_null_atom) {
-    AXObject* label_ax_object = CorrespondingLabelAXObject();
-    // If the label is set to be focusable, we should expose it.
-    if (label_ax_object && label_ax_object->CanSetFocusAttribute())
-      return kIncludeObject;
-
+          label, AOMStringProperty::kRole) == g_null_atom) {
     if (ignored_reasons) {
-      if (label_ax_object && label_ax_object != this)
+      if (label && label != GetNode()) {
+        AXObject* label_ax_object = AXObjectCache().GetOrCreate(label);
         ignored_reasons->push_back(
             IgnoredReason(kAXLabelContainer, label_ax_object));
+      }
 
-      ignored_reasons->push_back(IgnoredReason(kAXLabelFor, control_ax_object));
+      ignored_reasons->push_back(IgnoredReason(kAXLabelFor, control_object));
     }
     return kIgnoreObject;
   }
@@ -2812,7 +2809,7 @@ void AXNodeObject::SetNode(Node* node) {
   node_ = node;
 }
 
-AXObject* AXNodeObject::CorrespondingControlAXObjectForLabelElement() const {
+AXObject* AXNodeObject::CorrespondingControlForLabelElement() const {
   HTMLLabelElement* label_element = LabelElementContainer();
   if (!label_element)
     return nullptr;
@@ -2830,14 +2827,6 @@ AXObject* AXNodeObject::CorrespondingControlAXObjectForLabelElement() const {
   return AXObjectCache().GetOrCreate(corresponding_control);
 }
 
-AXObject* AXNodeObject::CorrespondingLabelAXObject() const {
-  HTMLLabelElement* label_element = LabelElementContainer();
-  if (!label_element)
-    return nullptr;
-
-  return AXObjectCache().GetOrCreate(label_element);
-}
-
 HTMLLabelElement* AXNodeObject::LabelElementContainer() const {
   if (!GetNode())
     return nullptr;

third_party/blink/renderer/modules/accessibility/ax_node_object.h

@@ -79,8 +79,7 @@ class MODULES_EXPORT AXNodeObject : public AXObject {
   Element* MouseButtonListener() const;
   bool IsNativeCheckboxOrRadio() const;
   void SetNode(Node*);
-  AXObject* CorrespondingControlAXObjectForLabelElement() const;
-  AXObject* CorrespondingLabelAXObject() const;
+  AXObject* CorrespondingControlForLabelElement() const;
   HTMLLabelElement* LabelElementContainer() const;
 
   //