Revert "Speculative fix for flaky webp encode/decode on Nexus 5"

This reverts commit 18a11a6f37.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Speculative fix for flaky webp encode/decode on Nexus 5
> 
> I'm not really expecting this to work anymore...
> 
> The docs don't say anything about the rgb pointer needing
> to stay valid, and it looks like we are done with it
> after the call to import.
> 
> Still, worth a try I think.
> 
> BUG=skia:5876
> 
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4024
> 
> Change-Id: I6e65ef96a2b661b01eb92bedab0acd73ed4f6218
> Reviewed-on: https://skia-review.googlesource.com/4024
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Matt Sarett <msarett@google.com>
> 

TBR=mtklein@chromium.org,msarett@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: Id764782ea58acc99e4719c0bff22619abaf9c6e5
Reviewed-on: https://skia-review.googlesource.com/4150
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Matt Sarett <msarett@google.com>

src/images/SkWEBPImageEncoder.cpp

@@ -227,10 +227,10 @@ bool SkWEBPImageEncoder::onEncode(SkWStream* stream, const SkBitmap& bm,
     } else {
         ok = SkToBool(WebPPictureImportRGBA(&pic, rgb, rgbStride));
     }
+    delete[] rgb;
 
     ok = ok && WebPEncode(&webp_config, &pic);
     WebPPictureFree(&pic);
-    delete[] rgb;
 
     return ok;
 }