Capture/Replay: Fix stride in compressed texture caching.

We were saving "width" bytes instead of "width * pixelSize". This was
causing incorrect rendering in T-Rex and Manhattan.

Bug: angleproject:4488
Change-Id: Ib5d38aaf813fb26905aedc155cc13b9d1597ec4c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2109336
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

Author: null77

src/libANGLE/FrameCapture.cpp

@@ -2813,7 +2813,7 @@ void FrameCapture::captureCompressedTextureData(const gl::Context *context, cons
             GLint y           = yindex + yoffset;
             GLint pixelOffset = zindex * pixelDepthPitch + yindex * pixelRowPitch;
             GLint levelOffset = z * levelDepthPitch + y * levelRowPitch + xoffset * pixelBytes;
-            memcpy(&levelData[levelOffset], &pixelData[pixelOffset], pixelWidth);
+            memcpy(&levelData[levelOffset], &pixelData[pixelOffset], pixelRowPitch);
         }
     }