Fixing uninitialized access in blink::ImagePattern::isLocalMatrixChanged

third_party/WebKit/Source/platform/graphics/ImagePattern.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/ImagePattern.h"
 
 #include "platform/graphics/Image.h"
 #include "platform/graphics/skia/SkiaUtils.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkShader.h"
 #include "third_party/skia/include/core/SkSurface.h"
 
 namespace blink {
 
 PassRefPtr<ImagePattern> ImagePattern::create(PassRefPtr<Image> image, RepeatMode repeatMode)
 {
     return adoptRef(new ImagePattern(image, repeatMode));
 }
 
 ImagePattern::ImagePattern(PassRefPtr<Image> image, RepeatMode repeatMode)
     : Pattern(repeatMode)
     , m_tileImage(toSkSp(image->imageForCurrentFrame()))
 {
+    m_previousLocalMatrix.setIdentity();
     if (m_tileImage) {
         // TODO(fmalita): mechanism to extract the actual SkImageInfo from an SkImage?
         const SkImageInfo info = SkImageInfo::MakeN32Premul(
             m_tileImage->width() + (isRepeatX() ? 0 : 2),
             m_tileImage->height() + (isRepeatY() ? 0 : 2));
         adjustExternalMemoryAllocated(info.getSafeSize(info.minRowBytes()));
     }
 }
 
 bool ImagePattern::isLocalMatrixChanged(const SkMatrix& localMatrix) const
@@ skipping 43 matching lines @@
 
     return surface->makeImageSnapshot()->makeShader(tileModeX, tileModeY, &adjustedMatrix);
 }
 
 bool ImagePattern::isTextureBacked() const
 {
     return m_tileImage && m_tileImage->isTextureBacked();
 }
 
 } // namespace blink