Don't expose Android set selection accessibility action for empty text fields

content/browser/accessibility/browser_accessibility_manager_android.cc

Index: content/browser/accessibility/browser_accessibility_manager_android.cc
diff --git a/content/browser/accessibility/browser_accessibility_manager_android.cc b/content/browser/accessibility/browser_accessibility_manager_android.cc
index df7361110a178fe0e03c4bd458df4bbaeacbbb1d..8a5a498f49a74d1c464e395b42e2219e66ec8a2a 100644
--- a/content/browser/accessibility/browser_accessibility_manager_android.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_android.cc
@@ -424,7 +424,8 @@ jboolean BrowserAccessibilityManagerAndroid::PopulateAccessibilityNodeInfo(
       node->IsFocusable(),
       node->IsFocused(),
       node->IsCollapsed(),
-      node->IsExpanded());
+      node->IsExpanded(),
+      !node->GetValue().empty());

[David Tseng, 2016/09/08 20:49:47]

If I understand the bug correctly, don't you want to check for the placeholder
attribute here?

[dmazzoni, 2016/10/05 19:40:48]

No, because placeholder was just one possible example of an accessible label for
the text field. The real issue is that we want to know whether it has a value or
not.

There was a bug in GetValue, though - it was sometimes returning inner text. I
fixed that and added tests.

[David Tseng, 2016/10/06 16:27:58]

Value comes from value description and string value in Blink. Value description
uses aria value text which I guess isn't selectable. String value uses the text
value of the text field which is selectable. If the node is a select, it uses
aria label, which isn't selectable.

In conclusion, I don't think value is a good indicator of what's selectable or
not. Also, are you expecting this gets called only on text fields? Is Talkback
thinking about supporting dom selections? Might be nice to be able to select a
link, for example, to paste into a Doc.

   Java_BrowserAccessibilityManager_setAccessibilityNodeInfoClassName(
       env, obj, info,
       base::android::ConvertUTF8ToJavaString(env, node->GetClassName()));