GN: Mojo wget, sample_app, surfaces app and component build

mojo/examples/BUILD.gn

Index: mojo/examples/BUILD.gn
diff --git a/components/history/core/common/BUILD.gn b/mojo/examples/BUILD.gn
similarity index 55%
copy from components/history/core/common/BUILD.gn
copy to mojo/examples/BUILD.gn
index 7a493141978ebc86786ede32720f563e8a537d74..f85f20fd3a79af2946766f7532cd9e98d84ae2aa 100644
--- a/components/history/core/common/BUILD.gn
+++ b/mojo/examples/BUILD.gn
@@ -2,13 +2,11 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-static_library("common") {
-  sources = [
-    "thumbnail_score.cc",
-    "thumbnail_score.h",
-  ]
-
+group("examples") {
   deps = [
-    "//base",
+    "//mojo/examples/echo",
+    "//mojo/examples/sample_app",
+    "//mojo/examples/surfaces_app",
+    "//mojo/examples/wget",
   ]
 }