Pass min/max page scale to compositor from WebFrameWidget.

third_party/WebKit/Source/web/WebFrameWidgetImpl.cpp

 /*
  * Copyright (C) 2014 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 243 matching lines @@
 
 void WebFrameWidgetImpl::paint(WebCanvas* canvas, const WebRect& rect) {
   // Out-of-process iframes require compositing.
   NOTREACHED();
 }
 
 void WebFrameWidgetImpl::updateLayerTreeViewport() {
   if (!page() || !m_layerTreeView)
     return;
 
-  // FIXME: We need access to page scale information from the WebView.
-  m_layerTreeView->setPageScaleFactorAndLimits(1, 1, 1);
+  m_layerTreeView->setPageScaleFactorAndLimits(
+      1, view()->minimumPageScaleFactor(), view()->maximumPageScaleFactor());

[bokan, 2016/11/03 14:55:50]

Is it ok that we'll be clobbering the page scale factor with 1 here?

 }
 
 void WebFrameWidgetImpl::updateLayerTreeBackgroundColor() {
   if (!m_layerTreeView)
     return;
 
   m_layerTreeView->setBackgroundColor(backgroundColor());
 }
 
 void WebFrameWidgetImpl::updateLayerTreeDeviceScaleFactor() {
@@ skipping 935 matching lines @@
   return nullptr;
 }
 
 LocalFrame* WebFrameWidgetImpl::focusedLocalFrameAvailableForIme() const {
   if (!m_imeAcceptEvents)
     return nullptr;
   return focusedLocalFrameInWidget();
 }
 
 }  // namespace blink