Fix SafeAdd and SafeMultiply

BUG=145648,145544


Review URL: https://chromiumcodereview.appspot.com/10916165

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@155478 0039d316-1c4b-4281-b951-d872f2087c98
bool GLES2DecoderImpl::DoIsRenderbuffer(GLuint client_id) {
  const RenderbufferManager::RenderbufferInfo* renderbuffer =
      GetRenderbufferInfo(client_id);
  return renderbuffer && renderbuffer->IsValid() && !renderbuffer->IsDeleted();
}

bool GLES2DecoderImpl::DoIsRenderbuffer(GLuint client_id) {
  const RenderbufferManager::RenderbufferInfo* renderbuffer =
      GetRenderbufferInfo(client_id);
  return renderbuffer && renderbuffer->IsValid() && !renderbuffer->IsDeleted();
}
