Enable accessible name of a control to include multiple <label> elements.

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

Index: third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
index c780186a855528cd7f12301a390698cbf61c3ff1..e33fd8df5f5625b48042c36ff3b7daf3386a9a05 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
@@ -51,6 +51,7 @@
 #include "core/html/HTMLOptionElement.h"
 #include "core/html/HTMLSelectElement.h"
 #include "core/html/HTMLTextAreaElement.h"
+#include "core/html/LabelsNodeList.h"
 #include "core/html/shadow/ShadowElementNames.h"
 #include "core/layout/HitTestResult.h"
 #include "core/layout/LayoutFieldset.h"
@@ -2463,12 +2464,17 @@ LayoutRect AXLayoutObject::computeElementRect() const
     if (isWebArea() && obj->frame()->view())
         result.setSize(LayoutSize(obj->frame()->view()->contentsSize()));
 
-    // Checkboxes and radio buttons include their label as part of their rect.
-    if (isCheckboxOrRadio()) {
-        HTMLLabelElement* label = labelForElement(toElement(m_layoutObject->node()));
-        if (label && label->layoutObject()) {
-            LayoutRect labelRect = axObjectCache().getOrCreate(label)->elementRect();
-            result.unite(labelRect);
+    // Checkboxes and radio buttons include their labels as part of their rect.
+    if (isCheckboxOrRadio() && isLabelableElement(obj->node())) {
+        LabelsNodeList* labels = toLabelableElement(obj->node())->labels();
+        if (labels) {
+            for (unsigned labelIndex = 0; labelIndex < labels->length(); ++labelIndex) {
+                AXObject* labelAXObject = axObjectCache().getOrCreate(labels->item(labelIndex));
+                if (labelAXObject) {
+                    LayoutRect labelRect = labelAXObject->elementRect();
+                    result.unite(labelRect);

[aboxhall, 2016/05/13 20:19:16]

This doesn't change in this change, but it never occurred to me until now that
this could be weird if there was some content between the labeled element and
its label. Not sure how likely that is to occur in practice.

[dmazzoni, 2016/05/13 22:22:42]

Agreed, it's a bit weird.

+                }
+            }
         }
     }