Relanding [Android] Adding Smart GO/NEXT feature in Chrome

third_party/WebKit/Source/core/page/FocusController.cpp

Index: third_party/WebKit/Source/core/page/FocusController.cpp
diff --git a/third_party/WebKit/Source/core/page/FocusController.cpp b/third_party/WebKit/Source/core/page/FocusController.cpp
index c5586d4bbeea1a6c2b0eecf5e7ea68b163766e20..9727a9b61e7539832a869ba03ff0c35b15e9b23e 100644
--- a/third_party/WebKit/Source/core/page/FocusController.cpp
+++ b/third_party/WebKit/Source/core/page/FocusController.cpp
@@ -47,6 +47,7 @@
 #include "core/frame/RemoteFrame.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLAreaElement.h"
+#include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLPlugInElement.h"
 #include "core/html/HTMLShadowElement.h"
@@ -54,6 +55,7 @@
 #include "core/html/TextControlElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/HitTestResult.h"
+#include "core/layout/LayoutObject.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/FocusChangedObserver.h"
 #include "core/page/FrameTree.h"
@@ -1066,6 +1068,51 @@ Element* FocusController::FindFocusableElement(WebFocusType type,
   return FindFocusableElementAcrossFocusScopes(type, scope);
 }
 
+Element* FocusController::NextFocusableElementInForm(Element* element,
+                                                     WebFocusType focus_type) {
+  element->GetDocument().UpdateStyleAndLayoutIgnorePendingStylesheets();
+  if (!element->IsHTMLElement())
+    return nullptr;
+
+  if (!element->IsFormControlElement() &&
+      !ToHTMLElement(element)->isContentEditableForBinding())
+    return nullptr;
+
+  HTMLFormElement* form_owner = nullptr;
+  if (ToHTMLElement(element)->isContentEditableForBinding())
+    form_owner = Traversal<HTMLFormElement>::FirstAncestor(*element);
+  else
+    form_owner = ToHTMLFormControlElement(element)->formOwner();
+
+  if (!form_owner)
+    return nullptr;
+
+  Element* next_element = element;
+  for (next_element = FindFocusableElement(focus_type, *next_element);
+       next_element;
+       next_element = FindFocusableElement(focus_type, *next_element)) {
+    if (!next_element->IsHTMLElement())
+      continue;
+    if (ToHTMLElement(next_element)->isContentEditableForBinding() &&
+        next_element->IsDescendantOf(form_owner))
+      return next_element;
+    if (!next_element->IsFormControlElement())
+      continue;
+    HTMLFormControlElement* form_element =
+        ToHTMLFormControlElement(next_element);
+    if (form_element->formOwner() != form_owner ||
+        form_element->IsDisabledOrReadOnly())
+      continue;
+    LayoutObject* layout = next_element->GetLayoutObject();
+    if (layout && layout->IsTextControl()) {
+      // TODO(ajith.v) Extend it for select elements, radio buttons and check
+      // boxes
+      return next_element;
+    }
+  }
+  return nullptr;
+}
+
 Element* FocusController::FindFocusableElementInShadowHost(
     const Element& shadow_host) {
   DCHECK(shadow_host.AuthorShadowRoot());