Improve text inputs focusing behaviour

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 2709 matching lines @@
     WebRect caret, unusedEnd;
     selectionBounds(caret, unusedEnd);
     IntRect unscaledCaret = caret;
     unscaledCaret.scale(1 / pageScaleFactor());
     caret = unscaledCaret;
 
     // Pick a scale which is reasonably readable. This is the scale at which
     // the caret height will become minReadableCaretHeight (adjusted for dpi
     // and font scale factor).
     newScale = clampPageScaleFactorToLimits(legibleScale() * minReadableCaretHeight / caret.height);
+    newScale = std::max(newScale, pageScaleFactor());
     const float deltaScale = newScale / pageScaleFactor();
 
     // Convert the rects to absolute space in the new scale.
     IntRect textboxRectInDocumentCoordinates = textboxRect;
     textboxRectInDocumentCoordinates.move(mainFrame()->scrollOffset());
     IntRect caretInDocumentCoordinates = caret;
     caretInDocumentCoordinates.move(mainFrame()->scrollOffset());
 
     int viewWidth = m_size.width / newScale;
     int viewHeight = m_size.height / newScale;
@@ skipping 18 matching lines @@
         // be offscreen, in which case bottom-align the caret.
         newScroll.setY(std::max<int>(textboxRectInDocumentCoordinates.y(), caretInDocumentCoordinates.y() + caretInDocumentCoordinates.height() + caretPadding - viewHeight));
     }
 
     needAnimation = false;
     // If we are at less than the target zoom level, zoom in.
     if (deltaScale > minScaleChangeToTriggerZoom)
         needAnimation = true;
     // If the caret is offscreen, then animate.
     IntRect sizeRect(0, 0, viewWidth, viewHeight);
+    sizeRect.scale(newScale / pageScaleFactor());
     if (!sizeRect.contains(caret))
         needAnimation = true;
     // If the box is partially offscreen and it's possible to bring it fully
     // onscreen, then animate.
     if (sizeRect.contains(textboxRectInDocumentCoordinates.width(), textboxRectInDocumentCoordinates.height()) && !sizeRect.contains(textboxRect))
         needAnimation = true;
 }
 
 void WebViewImpl::advanceFocus(bool reverse)
 {
@@ skipping 1497 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink