Properly prioritize the sources of an accessible name on Android.

This spec covers the right order: http://www.w3.org/TR/wai-aria-implementation

Now Android basically matches Windows, the difference is that Android has
to pick just one accessible name while Windows can have both a name and
a description.

There were existing cross-platform tests; I updated the Android
expectations.

BUG=359216

Review URL: https://codereview.chromium.org/303113003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274017 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/accessibility/browser_accessibility_android.cc

@@ -268,12 +268,29 @@ base::string16 BrowserAccessibilityAndroid::GetText() const {
     return base::string16();
   }
 
+  // See comment in browser_accessibility_win.cc for details.
+  // The difference here is that we can only expose one accessible
+  // name on Android, not 2 or 3 like on Windows or Mac.
+  //
+  // The basic rule is: prefer description (aria-labelledby or aria-label),
+  // then help (title), then name (inner text), then value (control value).
+  // However, if title_elem_id is set, that means there's a label element
+  // supplying the name and then name takes precedence over help.
+  // TODO(dmazzoni): clean this up by providing more granular labels in
+  // Blink, making the platform-specific mapping to accessible text simpler.
   base::string16 description = GetString16Attribute(ui::AX_ATTR_DESCRIPTION);
+  base::string16 help = GetString16Attribute(ui::AX_ATTR_HELP);
+  int title_elem_id = GetIntAttribute(
+      ui::AX_ATTR_TITLE_UI_ELEMENT);
   base::string16 text;
-  if (!name().empty())
-    text = base::UTF8ToUTF16(name());
-  else if (!description.empty())
+  if (!description.empty())
     text = description;
+  else if (title_elem_id && !name().empty())
+    text = base::UTF8ToUTF16(name());
+  else if (!help.empty())
+    text = help;
+  else if (!name().empty())
+    text = base::UTF8ToUTF16(name());
   else if (!value().empty())
     text = base::UTF8ToUTF16(value());
 

content/test/data/accessibility/button-name-calc-expected-android.txt

-#<skip - this is definitely wrong
 android.webkit.WebView focusable focused scrollable
     android.view.View
         android.widget.Button clickable focusable name='InnerText0'
-        android.widget.Button clickable focusable name='InnerText1'
-        android.widget.Button clickable focusable name='InnerText2'
-        android.widget.Button clickable focusable name='InnerText3'
-        android.widget.Button clickable focusable name='InnerText4'
-        android.widget.Button clickable focusable name='InnerText5'
+        android.widget.Button clickable focusable name='Title1'
+        android.widget.Button clickable focusable name='AriaLabel2'
+        android.widget.Button clickable focusable name='LabelledBy3'
+        android.widget.Button clickable focusable name='LabelledBy4'
+        android.widget.Button clickable focusable name='DescribedBy5'

content/test/data/accessibility/checkbox-name-calc-expected-android.txt

-#<skip - last one should be DescribedBy5
 android.webkit.WebView focusable focused scrollable
     android.view.View
         android.widget.CheckBox checkable clickable focusable name='Title0'
-        android.widget.CheckBox checkable clickable focusable name='Label1'
+        android.widget.CheckBox checkable clickable focusable name='Title1'
         android.widget.CheckBox checkable clickable focusable name='AriaLabel2'
         android.widget.CheckBox checkable clickable focusable name='LabelledBy3'
         android.widget.CheckBox checkable clickable focusable name='LabelledBy4'
-        android.widget.CheckBox checkable focusable
+        android.widget.CheckBox checkable clickable focusable name='DescribedBy5'

content/test/data/accessibility/input-text-name-calc-expected-android.txt

-#<skip - calc is wrong
 android.webkit.WebView focusable focused scrollable
     android.view.View
-        android.widget.EditText clickable editable_text focusable name='Title0'
-        android.widget.EditText clickable editable_text focusable name='Title1'
-        android.widget.EditText clickable editable_text focusable name='Label2'
-        android.widget.EditText clickable editable_text focusable name='Label3'
-        android.widget.EditText editable_text focusable
-        android.widget.EditText clickable editable_text focusable name='Title5'
-        android.widget.EditText clickable editable_text focusable name='Label6'
+        android.widget.EditText clickable editable_text focusable name='Title0' input_type=1
+        android.widget.EditText clickable editable_text focusable name='Title1' input_type=1
+        android.widget.EditText clickable editable_text focusable name='AriaLabel2' input_type=1
+        android.widget.EditText clickable editable_text focusable name='LabelledBy3' input_type=1
+        android.widget.EditText editable_text focusable input_type=1
+        android.widget.EditText clickable editable_text focusable name='Title5' input_type=1
+        android.widget.EditText clickable editable_text focusable name='LabelledBy6' input_type=1