Change filter quality when scaling-down in drawImage

third_party/WebKit/Source/platform/graphics/StaticBitmapImage.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/graphics/StaticBitmapImage.h"
 
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/ImageObserver.h"
 #include "public/platform/Platform.h"
@@ skipping 43 matching lines @@
 {
     return m_image && m_image->isTextureBacked();
 }
 
 bool StaticBitmapImage::currentFrameKnownToBeOpaque(MetadataMode)
 {
     return m_image->isOpaque();
 }
 
 void StaticBitmapImage::draw(SkCanvas* canvas, const SkPaint& paint, const FloatRect& dstRect,
-    const FloatRect& srcRect, RespectImageOrientationEnum, ImageClampingMode clampMode)
+    const FloatRect& srcRect, bool imageSmoothingEnabled, RespectImageOrientationEnum, ImageClampingMode clampMode)
 {
     FloatRect adjustedSrcRect = srcRect;
     adjustedSrcRect.intersect(SkRect::Make(m_image->bounds()));
 
     if (dstRect.isEmpty() || adjustedSrcRect.isEmpty())
         return; // Nothing to draw.
 
-    canvas->drawImageRect(m_image.get(), adjustedSrcRect, dstRect, &paint,
+    SkPaint adjustedPaint = paint;
+    if (!imageSmoothingEnabled && Image::isDrawScalingDown(adjustedSrcRect, dstRect))
+        adjustedPaint.setFilterQuality(kLow_SkFilterQuality);
+
+    canvas->drawImageRect(m_image.get(), adjustedSrcRect, dstRect, &adjustedPaint,
         WebCoreClampingModeToSkiaRectConstraint(clampMode));
 
     if (ImageObserver* observer = getImageObserver())
         observer->didDraw(this);
 }
 
 GLuint StaticBitmapImage::switchStorageToSkImage(WebGraphicsContext3DProvider* provider)
 {
     if (!provider)
         return 0;
@@ skipping 92 matching lines @@
     // Has mailbox, consume mailbox, prepare a new mailbox if contextProvider is not null (3D).
     DCHECK(isMainThread());
     // TODO(xidachen): make this work on a worker thread.
     std::unique_ptr<WebGraphicsContext3DProvider> sharedProvider = wrapUnique(Platform::current()->createSharedOffscreenGraphicsContext3DProvider());
     if (!switchStorageToSkImage(sharedProvider.get()))
         return nullptr;
     return m_image;
 }
 
 } // namespace blink