Use CHECK_EQ to get better error message

Make SkiaGLImageRepresentation::CheckContext() use CHECK_EQ so it prints
both values on error.

Bug: 1359024
Change-Id: Ie686e7ff158317d34ea8865ea7efc2976fa1c843
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3880263
Auto-Submit: Kyle Charbonneau <kylechar@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Kyle Charbonneau <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1044358}

gpu/command_buffer/service/shared_image/skia_gl_image_representation.cc

@@ -161,7 +161,7 @@ void SkiaGLImageRepresentation::EndReadAccess() {
 
 void SkiaGLImageRepresentation::CheckContext() {
 #if DCHECK_IS_ON()
-  DCHECK(gl::GLContext::GetCurrent() == context_);
+  DCHECK_EQ(gl::GLContext::GetCurrent(), context_);
 #endif
 }