[blink] Support (semi-)transparent background colors in WebView/Frame.

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 156 matching lines @@
       m_hasPendingLayout(false),
       m_inSynchronousPostLayout(false),
       m_postLayoutTasksTimer(
           TaskRunnerHelper::get(TaskType::UnspecedTimer, &frame),
           this,
           &FrameView::postLayoutTimerFired),
       m_updatePluginsTimer(
           TaskRunnerHelper::get(TaskType::UnspecedTimer, &frame),
           this,
           &FrameView::updatePluginsTimerFired),
-      m_isTransparent(false),
       m_baseBackgroundColor(Color::white),
       m_mediaType(MediaTypeNames::screen),
       m_safeToPropagateScrollToParent(true),
       m_scrollCorner(nullptr),
       m_stickyPositionObjectCount(0),
       m_inputEventsScaleFactorForEmulation(1),
       m_layoutSizeFixedToFrameSize(true),
       m_didScrollTimer(TaskRunnerHelper::get(TaskType::UnspecedTimer, &frame),
                        this,
                        &FrameView::didScrollTimerFired),
@@ skipping 2130 matching lines @@
   LayoutViewItem layoutViewItem = this->layoutViewItem();
   if (layoutViewItem.isNull())
     return;
   // TODO(crbug.com/590856): It's still broken if we choose not to crash when
   // the check fails.
   if (!checkLayoutInvalidationIsAllowed())
     return;
   layoutViewItem.setNeedsLayout(LayoutInvalidationReason::Unknown);
 }
 
-bool FrameView::isTransparent() const {
-  return m_isTransparent;
-}
-
-void FrameView::setTransparent(bool isTransparent) {
-  m_isTransparent = isTransparent;
-  DisableCompositingQueryAsserts disabler;
-  if (!layoutViewItem().isNull() &&
-      layoutViewItem().layer()->hasCompositedLayerMapping())
-    layoutViewItem().layer()->compositedLayerMapping()->updateContentsOpaque();
-}
-
 bool FrameView::hasOpaqueBackground() const {
-  return !m_isTransparent && !m_baseBackgroundColor.hasAlpha();
+  return !m_baseBackgroundColor.hasAlpha();
 }
 
 Color FrameView::baseBackgroundColor() const {
   return m_baseBackgroundColor;
 }
 
 void FrameView::setBaseBackgroundColor(const Color& backgroundColor) {
   m_baseBackgroundColor = backgroundColor;
 
   if (!layoutViewItem().isNull() &&
       layoutViewItem().layer()->hasCompositedLayerMapping()) {
     CompositedLayerMapping* compositedLayerMapping =
         layoutViewItem().layer()->compositedLayerMapping();
     compositedLayerMapping->updateContentsOpaque();
     if (compositedLayerMapping->mainGraphicsLayer())
       compositedLayerMapping->mainGraphicsLayer()->setNeedsDisplay();
   }
   recalculateScrollbarOverlayColorTheme(documentBackgroundColor());
 
   if (!shouldThrottleRendering())
     page()->animator().scheduleVisualUpdate(m_frame.get());
 }
 
-void FrameView::updateBackgroundRecursively(const Color& backgroundColor,
-                                            bool transparent) {
-  forAllNonThrottledFrameViews(
-      [backgroundColor, transparent](FrameView& frameView) {
-        frameView.setTransparent(transparent);
-        frameView.setBaseBackgroundColor(backgroundColor);
-      });
+void FrameView::updateBaseBackgroundColorRecursively(
+    const Color& baseBackgroundColor) {
+  forAllNonThrottledFrameViews([baseBackgroundColor](FrameView& frameView) {
+    frameView.setBaseBackgroundColor(baseBackgroundColor);
+  });
 }
 
 void FrameView::scrollToFragmentAnchor() {
   Node* anchorNode = m_fragmentAnchor;
   if (!anchorNode)
     return;
 
   // Scrolling is disabled during updateScrollbars (see
   // isProgrammaticallyScrollable).  Bail now to avoid clearing m_fragmentAnchor
   // before we actually have a chance to scroll.
@@ skipping 2875 matching lines @@
 void FrameView::setAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   m_animationHost = std::move(host);
 }
 
 LayoutUnit FrameView::caretWidth() const {
   return LayoutUnit(getHostWindow()->windowToViewportScalar(1));
 }
 
 }  // namespace blink