[PDF] Fix image references.

Chrome doesn't seem to honor the reference to the pixel ref. A copy is necessary for unpremultiplication anyway, so pull that part in now.

BUG=chromium:279640
R=reed@google.com

Author: vandebo@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23730003

git-svn-id: http://skia.googlecode.com/svn/trunk@11014 2bbb7eff-a529-9590-31e7-b0007b416f81

src/pdf/SkPDFImage.cpp

@@ -391,11 +391,17 @@ SkPDFImage::SkPDFImage(SkStream* stream,
                        bool isAlpha,
                        const SkIRect& srcRect,
                        EncodeToDCTStream encoder)
-    : fBitmap(bitmap),
-      fIsAlpha(isAlpha),
+    : fIsAlpha(isAlpha),
       fSrcRect(srcRect),
       fEncoder(encoder) {
 
+    if (bitmap.isImmutable()) {
+        fBitmap = bitmap;
+    } else {
+        bitmap.deepCopyTo(&fBitmap, bitmap.config());
+        fBitmap.setImmutable();
+    }
+
     if (stream != NULL) {
         setData(stream);
         fStreamValid = true;