scroll into view considers layers

LayerAndroid.*
- Add a utility that takes the given rectangle and subtracts
  layers that overlay it.

FindCanvas.*
- Add function that returns if the current match is on the
  main page or in a layer.

WebView.cpp
- Add jni caller for WebView.java calcOurContentVisibleRect.
  Call it instead of getVisibleRect, which has the side effect
  of sending messages back to webkit.
- Remove jni caller for getViewMetrics, since it is redundant.
- Only call scrollRectOnScreen for non-layers.

companion fix in framework/base

http://b/2485168
5 files changed