Rename mojo_html_viewer target to just html_viewer.

mojo/services/html_viewer/BUILD.gn

Index: mojo/services/html_viewer/BUILD.gn
diff --git a/mojo/services/html_viewer/BUILD.gn b/mojo/services/html_viewer/BUILD.gn
index 31bc4d4ab525fcf4b480bd75b8dfcb0714e4506c..44557e2e48044ed8259e163e398def084cb6c9f1 100644
--- a/mojo/services/html_viewer/BUILD.gn
+++ b/mojo/services/html_viewer/BUILD.gn
@@ -2,10 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# GYP version: mojo/mojo_services.gypi:mojo_html_viewer
+# GYP version: mojo/mojo_services.gypi:html_viewer
 shared_library("html_viewer") {
-  output_name = "mojo_html_viewer"
-
   sources = [
     "blink_basic_type_converters.cc",
     "blink_basic_type_converters.h",