[devtools] Allow transparent base background color overrides.

third_party/WebKit/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 354 matching lines @@
       m_tabsToLinks(false),
       m_layerTreeView(nullptr),
       m_rootLayer(nullptr),
       m_rootGraphicsLayer(nullptr),
       m_visualViewportContainerLayer(nullptr),
       m_matchesHeuristicsForGpuRasterization(false),
       m_flingModifier(0),
       m_flingSourceDevice(WebGestureDeviceUninitialized),
       m_fullscreenController(FullscreenController::create(this)),
       m_baseBackgroundColor(Color::white),
+      m_baseBackgroundColorOverrideEnabled(false),
       m_baseBackgroundColorOverride(Color::transparent),
       m_backgroundColorOverride(Color::transparent),
       m_zoomFactorOverride(0),
       m_userGestureObserved(false),
       m_shouldDispatchFirstVisuallyNonEmptyLayout(false),
       m_shouldDispatchFirstLayoutAfterFinishedParsing(false),
       m_shouldDispatchFirstLayoutAfterFinishedLoading(false),
       m_displayMode(WebDisplayModeBrowser),
       m_elasticOverscroll(FloatSize()),
       m_mutator(nullptr),
@@ skipping 2054 matching lines @@
     // plugins/mouse-capture-inside-shadow.html reaches here.
     return false;
   }
   return selection.computeVisibleSelectionInDOMTreeDeprecated().isBaseFirst();
 }
 
 WebColor WebViewImpl::backgroundColor() const {
   if (isTransparent())
     return Color::transparent;
   if (!m_page)
-    return m_baseBackgroundColor;
+    return baseBackgroundColor().rgb();

[dgozman, 2017/02/21 19:41:44]

Nice one!

[Eric Seckler, 2017/02/22 09:19:30]

yeah ... I should have seen that in the first place really :)

   if (!m_page->mainFrame())
-    return m_baseBackgroundColor;
+    return baseBackgroundColor().rgb();
   if (!m_page->mainFrame()->isLocalFrame())
-    return m_baseBackgroundColor;
+    return baseBackgroundColor().rgb();
   FrameView* view = m_page->deprecatedLocalMainFrame()->view();
   return view->documentBackgroundColor().rgb();
 }
 
 WebPagePopup* WebViewImpl::pagePopup() const {
   return m_pagePopup.get();
 }
 
 // TODO(ekaramad):This method is almost duplicated in WebFrameWidgetImpl as
 // well. This code needs to be refactored  (http://crbug.com/629721).
@@ skipping 1059 matching lines @@
 bool WebViewImpl::isTransparent() const {
   return m_isTransparent;
 }
 
 WebInputMethodControllerImpl* WebViewImpl::getActiveWebInputMethodController()
     const {
   return WebInputMethodControllerImpl::fromFrame(focusedLocalFrameInWidget());
 }
 
 Color WebViewImpl::baseBackgroundColor() const {
-  return alphaChannel(m_baseBackgroundColorOverride)
-             ? m_baseBackgroundColorOverride
-             : m_baseBackgroundColor;
+  return m_baseBackgroundColorOverrideEnabled ? m_baseBackgroundColorOverride
+                                              : m_baseBackgroundColor;
 }
 
 void WebViewImpl::setBaseBackgroundColor(WebColor color) {
   if (m_baseBackgroundColor == color)
     return;
 
   m_baseBackgroundColor = color;
   updateBaseBackgroundColor();
 }
 
 void WebViewImpl::setBaseBackgroundColorOverride(WebColor color) {
+  m_baseBackgroundColorOverrideEnabled = true;
   m_baseBackgroundColorOverride = color;
   if (mainFrameImpl()) {
     // Force lifecycle update to ensure we're good to call
     // FrameView::setBaseBackgroundColor().
     mainFrameImpl()
         ->frame()
         ->view()
         ->updateLifecycleToCompositingCleanPlusScrolling();
   }
   updateBaseBackgroundColor();
 }
 
+void WebViewImpl::clearBaseBackgroundColorOverride() {
+  m_baseBackgroundColorOverrideEnabled = false;
+  if (mainFrameImpl()) {
+    // Force lifecycle update to ensure we're good to call
+    // FrameView::setBaseBackgroundColor().
+    mainFrameImpl()
+        ->frame()
+        ->view()
+        ->updateLifecycleToCompositingCleanPlusScrolling();
+  }
+  updateBaseBackgroundColor();
+}
+
 void WebViewImpl::updateBaseBackgroundColor() {
   Color color = baseBackgroundColor();
   if (m_page->mainFrame() && m_page->mainFrame()->isLocalFrame())
     m_page->deprecatedLocalMainFrame()->view()->setBaseBackgroundColor(color);
 }
 
 void WebViewImpl::setIsActive(bool active) {
   if (page())
     page()->focusController().setActive(active);
 }
@@ skipping 573 matching lines @@
   if (focusedFrame->localFrameRoot() != mainFrameImpl()->frame())
     return nullptr;
   return focusedFrame;
 }
 
 LocalFrame* WebViewImpl::focusedLocalFrameAvailableForIme() const {
   return m_imeAcceptEvents ? focusedLocalFrameInWidget() : nullptr;
 }
 
 }  // namespace blink