Added a non-null check in the constructor of StaticBitmapImage

BUG=421033

Review URL: https://codereview.chromium.org/660383003

git-svn-id: svn://svn.chromium.org/blink/trunk@184006 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -21,6 +21,7 @@ PassRefPtr<Image> StaticBitmapImage::create(PassRefPtr<SkImage> image)
 
 StaticBitmapImage::StaticBitmapImage(PassRefPtr<SkImage> image) : m_image(image)
 {
+    ASSERT(m_image);
 }
 
 StaticBitmapImage::~StaticBitmapImage() { }