gn: Make command_buffer_gles2 deps less weird.

The target used to pull in source_sets that are part of the gpu
component in component builds.  This usually won't link well, so
just depend on gpu directly.

Happens to fix a build error in clang/win gn component builds too.

BUG=82385
TBR=dpranke

Review URL: https://codereview.chromium.org/1542683002

Cr-Commit-Position: refs/heads/master@{#366450}
1 file changed