Workaround bad bitmaps in clibpoard code

content/renderer/webclipboard_impl.cc

Index: content/renderer/webclipboard_impl.cc
diff --git a/content/renderer/webclipboard_impl.cc b/content/renderer/webclipboard_impl.cc
index 317ec7d283d707849e2829b8035760fd2530d4b7..914febfa44d88968d243a8c78ffc9963150f1734 100644
--- a/content/renderer/webclipboard_impl.cc
+++ b/content/renderer/webclipboard_impl.cc
@@ -155,8 +155,16 @@ void WebClipboardImpl::writeImage(const WebImage& image,
 
   if (!image.isNull()) {
     const SkBitmap& bitmap = image.getSkBitmap();
+
+    // WriteBitmapFromPixels expects 32-bit data.
+    if (bitmap.config() != SkBitmap::kARGB_8888_Config)

[dcheng, 2014/05/19 19:44:59]

Hm... are you aware of any cases where we don't pass in an ARGB bitmap?
Otherwise, it seems to me like this should be a CHECK or DCHECK.

[piman, 2014/05/19 19:45:56]

Can't it be arbitrary?
E.g. what if the png is grayscale?

[dcheng, 2014/05/19 19:51:01]

I'm not an expert in this area, but this is the decoded bits of the image. I
would assume we always decode to a 32-bit ARGB to keep things simple.

[piman, 2014/05/19 22:50:00]

I'm not sure we want to make assumptions about code that is far far away in
another repo, when that assumption has security implications - see bug. Even if
it's true today, is there a test that verifies that it will stay true forever?

[piman, 2014/05/20 06:48:47]

OK, replaced by a DCHECK.

+      return;
     SkAutoLockPixels locked(bitmap);
-    scw.WriteBitmapFromPixels(bitmap.getPixels(), image.size());
+    void *pixels = bitmap.getPixels();
+    // TODO(piman): this should not be NULL, but it is. crbug.com/369621
+    if (!pixels)
+      return;
+    scw.WriteBitmapFromPixels(pixels, image.size());
   }
 
   if (!url.isEmpty()) {