Merge 117191 - Assertion failure running Mozilla's WebGL performance regression tests

Source/WebCore/platform/graphics/cairo/GraphicsContext3DCairo.cpp

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 Igalia S.L.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 167 matching lines @@
     unsigned int srcUnpackAlignment = 1;
     size_t bytesPerRow = cairo_image_surface_get_stride(imageSurface.get());
     size_t bitsPerPixel = 32;
     unsigned int padding = bytesPerRow - bitsPerPixel / 8 * width;
     if (padding) {
         srcUnpackAlignment = padding + 1;
         while (bytesPerRow % srcUnpackAlignment)
             ++srcUnpackAlignment;
     }
 
-    outputVector.resize(width * height * 4);
+    unsigned int packedSize;
+    // Output data is tightly packed (alignment == 1).
+    if (computeImageSizeInBytes(format, type, width, height, 1, &packedSize, 0) != GraphicsContext3D::NO_ERROR)
+        return false;
+    outputVector.resize(packedSize);
+
     return packPixels(cairo_image_surface_get_data(imageSurface.get()), SourceFormatBGRA8,
                       width, height, srcUnpackAlignment, format, type, alphaOp, outputVector.data());
 }
 
 void GraphicsContext3D::paintToCanvas(const unsigned char* imagePixels, int imageWidth, int imageHeight, int canvasWidth, int canvasHeight, PlatformContextCairo* context)
 {
     if (!imagePixels || imageWidth <= 0 || imageHeight <= 0 || canvasWidth <= 0 || canvasHeight <= 0 || !context)
         return;
 
     cairo_t *cr = context->cr();
@@ skipping 45 matching lines @@
 #if USE(ACCELERATED_COMPOSITING)
 PlatformLayer* GraphicsContext3D::platformLayer() const
 {
     return m_private.get();
 }
 #endif
 
 } // namespace WebCore
 
 #endif // ENABLE(WEBGL)