Expose the selection root bounds in WebView.

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 8836341267581ea88fede135a0af516a7b3bfb95..84bf1280003174f64e65eada81cd86d4a4fac294 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -2144,6 +2144,34 @@ bool WebViewImpl::selectionBounds(WebRect& anchor, WebRect& focus) const
     return true;
 }
 
+bool WebViewImpl::selectionRootBounds(WebRect& bounds) const
+{
+    const LocalFrame* frame = focusedWebCoreFrame();
+    if (!frame)
+        return false;
+
+    Element* root = frame->selection().rootEditableElementOrDocumentElement();
+    if (!root)
+        return false;
+
+    // If the selection is inside a form control, the root will be a <div> that
+    // behaves as the editor but we want to return the actual element's bounds.
+    // In practice, that means <textarea> and <input> controls that behave like
+    // a text field.
+    if (root->shadowHost()
+        && (root->shadowHost()->hasTagName(HTMLNames::textareaTag)
+            || (root->shadowHost()->hasTagName(HTMLNames::inputTag)
+                && toHTMLInputElement(root->shadowHost())->isText())))
+        root = root->shadowHost();
+
+    IntRect boundingBox = root->pixelSnappedBoundingBox();
+    boundingBox = root->document().frame()->view()->contentsToWindow(boundingBox);
+    boundingBox.scale(pageScaleFactor());
+    bounds = boundingBox;
+
+    return true;
+}
+
 InputMethodContext* WebViewImpl::inputMethodContext()
 {
     if (!m_imeAcceptEvents)