[PE] Fix a null ptr access in ImageBitmap

The ImageBitmap constructor that takes pixel data and a width and
height does not check for success of the skia MakeRasterCopy call,
that will return null for a host of reasons. Add the check.

R=junov@chromium.org
BUG=805972

Null check in ImageBitmap:ImageBitmap

Change-Id: I4cd8464b21c3b14488ae8a948864b091f17d006a
Reviewed-on: https://chromium-review.googlesource.com/887678Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532976}

third_party/WebKit/Source/core/imagebitmap/ImageBitmap.cpp

@@ -595,7 +595,10 @@ ImageBitmap::ImageBitmap(const void* pixel_data,
                                                       : kUnpremul_SkAlphaType,
                         color_params.GetSkColorSpaceForSkSurfaces());
   SkPixmap pixmap(info, pixel_data, info.bytesPerPixel() * width);
-  image_ = StaticBitmapImage::Create(SkImage::MakeRasterCopy(pixmap));
+  sk_sp<SkImage> raster_copy = SkImage::MakeRasterCopy(pixmap);
+  if (!raster_copy)
+    return;
+  image_ = StaticBitmapImage::Create(std::move(raster_copy));
   if (!image_)
     return;
   image_->SetOriginClean(is_image_bitmap_origin_clean);