Fix unpack parameter validation.

BUG=angleproject:1397

Change-Id: Icdfc99eefcfad730ec887b82ec0758a6d6c0b9a7
Reviewed-on: https://chromium-review.googlesource.com/348064
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/validationES2.cpp b/src/libANGLE/validationES2.cpp
index 5001050..2ddda21 100644
--- a/src/libANGLE/validationES2.cpp
+++ b/src/libANGLE/validationES2.cpp
@@ -1831,7 +1831,7 @@
 
     const InternalFormat &formatInfo = GetInternalFormatInfo(internalformat);
     auto blockSizeOrErr =
-        formatInfo.computeBlockSize(GL_UNSIGNED_BYTE, gl::Extents(width, height, 1));
+        formatInfo.computeCompressedImageSize(GL_UNSIGNED_BYTE, gl::Extents(width, height, 1));
     if (blockSizeOrErr.isError())
     {
         context->handleError(blockSizeOrErr.getError());
@@ -1879,7 +1879,7 @@
 
     const InternalFormat &formatInfo = GetInternalFormatInfo(format);
     auto blockSizeOrErr =
-        formatInfo.computeBlockSize(GL_UNSIGNED_BYTE, gl::Extents(width, height, 1));
+        formatInfo.computeCompressedImageSize(GL_UNSIGNED_BYTE, gl::Extents(width, height, 1));
     if (blockSizeOrErr.isError())
     {
         context->handleError(blockSizeOrErr.getError());