Comply Compositing spec [1]; remove 'plus-darker'.

Source/core/html/canvas/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 29 matching lines @@
 #include "core/css/CSSFontSelector.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/parser/CSSParser.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/StyleEngine.h"
 #include "core/events/Event.h"
 #include "core/fetch/ImageResource.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/Settings.h"
-#include "core/frame/UseCounter.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/ImageData.h"
 #include "core/html/TextMetrics.h"
 #include "core/html/canvas/CanvasGradient.h"
 #include "core/html/canvas/CanvasPattern.h"
 #include "core/html/canvas/CanvasStyle.h"
 #include "core/html/canvas/Path2D.h"
@@ skipping 698 matching lines @@
 {
     return compositeOperatorName(state().m_globalComposite, state().m_globalBlend);
 }
 
 void CanvasRenderingContext2D::setGlobalCompositeOperation(const String& operation)
 {
     CompositeOperator op = CompositeSourceOver;
     WebBlendMode blendMode = WebBlendModeNormal;
     if (!parseCompositeAndBlendOperator(operation, op, blendMode))
         return;
-    // crbug.com/425628: Count the use of "darker" to remove it.
-    if (op == CompositePlusDarker)
-        UseCounter::count(canvas()->document(), UseCounter::CanvasRenderingContext2DCompositeOperationDarker);
     if ((state().m_globalComposite == op) && (state().m_globalBlend == blendMode))
         return;
     GraphicsContext* c = drawingContext();
     realizeSaves(c);
     modifiableState().m_globalComposite = op;
     modifiableState().m_globalBlend = blendMode;
     if (!c)
         return;
     c->setCompositeOperation(op, blendMode);
 }
@@ skipping 1595 matching lines @@
 
 unsigned CanvasRenderingContext2D::hitRegionsCount() const
 {
     if (m_hitRegionManager)
         return m_hitRegionManager->getHitRegionsCount();
 
     return 0;
 }
 
 } // namespace blink