Streamline the presentation of ImageBitmapRenderingContext

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
@@ skipping 154 matching lines @@
   CHECK(m_stateStack.front()
             .get());  // Temporary for investigating crbug.com/648510
 }
 
 bool CanvasRenderingContext2D::isAccelerated() const {
   if (!canvas()->hasImageBuffer())
     return false;
   return canvas()->buffer()->isAccelerated();
 }
 
+bool CanvasRenderingContext2D::isComposited() const {
+  return isAccelerated();

[xlai (Olivia), 2017/03/09 21:57:27]

Your CL is about decoupling canvas being composited and being accelerated. Why
are they equivalent in here then?

[Justin Novosad, 2017/03/10 21:09:59]

For 2D canvas and WebGL, they are equivalent, but at the higher abstraction
level (CanvasRenderingContext), they are not.  The is because of the change to
ImageBitmapRenderingContext.

+}
+
 void CanvasRenderingContext2D::stop() {
   if (!isContextLost()) {
     // Never attempt to restore the context because the page is being torn down.
     loseContext(SyntheticLostContext);
   }
 }
 
 bool CanvasRenderingContext2D::isContextLost() const {
   return m_contextLostMode != NotLostContext;
 }
@@ skipping 633 matching lines @@
 
   if (!std::isfinite(x) || !std::isfinite(y))
     return;
   if (maxWidth && (!std::isfinite(*maxWidth) || *maxWidth <= 0))
     return;
 
   // Currently, SkPictureImageFilter does not support subpixel text
   // anti-aliasing, which is expected when !creationAttributes().alpha(), so we
   // need to fall out of display list mode when drawing text to an opaque
   // canvas. crbug.com/583809
-  if (!creationAttributes().alpha() && !isAccelerated()) {
+  if (!creationAttributes().alpha() && !isComposited()) {
     canvas()->disableDeferral(
         DisableDeferralReasonSubPixelTextAntiAliasingSupport);
   }
 
   const Font& font = accessFont();
   font.getFontDescription().setSubpixelAscentDescent(true);
   const SimpleFontData* fontData = font.primaryFont();
   DCHECK(fontData);
   if (!fontData)
     return;
@@ skipping 320 matching lines @@
   }
   return true;
 }
 
 void CanvasRenderingContext2D::resetUsageTracking() {
   UsageCounters newCounters;
   m_usageCounters = newCounters;
 }
 
 }  // namespace blink