Revert of Clean up the top level BUILD.gn file.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 343a2b428bb48d3e67f93d6c12f45166a6570392..cc4e52ac0781835d6188448b810228b8dd04a6eb 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -22,17 +22,34 @@
   root_extra_deps = []
 }
 
-# The "gn_all" target should list every root target (target that
-# nothing else depends on) built by both GN and GYP. One should
-# be able to run 'ninja gn_all gn_only gn_groups' and then run
-# 'ninja' a second time and have the second ninja invocation do nothing.
-#
-# In addition, the "gn_all" target serves to pull in all of the other
-# build files needed for the build.
-#
-# TODO(GYP): make sure that the above is true and there are scripts run
-# on the bots that enforce this.
-
+group("gyp_all") {
+  testonly = true
+
+  # TODO(GYP): This target should describe everything that is built by a GYP
+  # build but not yet by a GN build, i.e., these are the targets that still
+  # need to be ported to GN. Eventually this target should be identical to
+  # gn_all.
+
+  deps = [
+    ":gn_all",
+    # "//chrome/test:chromedriver_unittests", # TODO(GYP)
+    # "//components:components_browsertests", # TODO(GYP)
+    # "//components/nacl:nacl_loader_unittests", # TODO(GYP)
+    # "//google_apis:google_apis_unittests", # TODO(GYP)
+    # "//ui/compositor:compositor_unittests", # TODO(GYP)
+    # "//device:device_unittests", # TODO(GYP)
+    # "//ppapi:ppapi_unittests", # TODO(GYP)
+    # "//remoting:remoting_unittests",  # TODO(GYP)
+  ]
+}
+
+# The "gn_all" target matches the "gn_all" target in build/all.gyp.
+# It is not (yet!) the same as building "all".
+# TODO(GYP): Make it be basically the same as building all, or at least
+# be sure that we don't want any of the stuff listed in gn_all to
+# be built by default.
+
+# In GN, a "group" is a dummy target that just lists other targets.
 group("gn_all") {
   testonly = true
 
@@ -58,25 +75,51 @@
     "//ipc/mojo:ipc_mojo_unittests",
     "//jingle:jingle_unittests",
     "//media:media_unittests",
+    "//media/mojo",  # only builds in mojo
     "//media/cast:cast_unittests",
     "//mojo",
     "//mojo/common:mojo_common_unittests",
+
+    # "//mojo/services/html_viewer:tests",  # TODO(GYP): Do we need this?
     "//net:net_unittests",
     "//ppapi/examples",  # TODO(GYP): What's the GYP equivalent?
     "//printing:printing_unittests",
     "//skia:skia_unittests",
     "//sql:sql_unittests",
     "//sync:sync_unit_tests",
-    "//third_party/WebKit/public:blink_tests",
+
+    # TODO(GYP): the Blink test targets should be public, but
+    # currently aren't. all_blink pulls them in, though.
+    # "//third_party/WebKit/Source/platform:heap_unittests",
+    # "//third_party/WebKit/Source/platform:platform_unittests",
+    # "//third_party/WebKit/Source/wtf:wtf_unittests",
+    "//third_party/WebKit/public:all_blink",
     "//third_party/cacheinvalidation:cacheinvalidation_unittests",
+
+    # TODO(GYP): This is needed only w/ cld_version==1. What configs set that?
+    "//third_party/cld",
     "//third_party/codesighs",
+
+    # TODO(GYP): This is needed only w/ use_system_fontconfig==0.
+    # What configs set that?
+    # "//third_party/fontconfig",
+
+    # TODO(GYP): This will be pulled in automatically when enable_webrtc==true.
+    # For now pull it in manually so that it doesn't regress.
+    "//third_party/libsrtp",
     "//third_party/mojo/src/mojo/edk/system:mojo_system_unittests",
     "//third_party/mojo/src/mojo/edk/test:mojo_public_bindings_unittests",
     "//third_party/mojo/src/mojo/edk/test:mojo_public_environment_unittests",
     "//third_party/mojo/src/mojo/edk/test:mojo_public_system_unittests",
     "//third_party/mojo/src/mojo/edk/test:mojo_public_utility_unittests",
     "//third_party/pdfium/samples:pdfium_test",
+
+    # TODO(GYP): Verify that this is no longer needed.
     "//third_party/smhasher:pmurhash",
+
+    # TODO(GYP): This will be pulled in automatically when enable_webrtc==true.
+    # For now pull it in manually so that it doesn't regress.
+    "//third_party/usrsctp",
     "//tools/imagediff($host_toolchain)",
     "//tools/gn",
     "//tools/gn:gn_unittests",
@@ -254,13 +297,6 @@
       "//net:net_unittests",  # TODO(GYP)
     ]
   }
-}
-
-group("gn_only") {
-  deps = [
-    "//media/mojo",
-    # "//mojo/services/html_viewer:tests",  # TODO(GYP): Do we need this?
-  ]
 }
 
 if (is_linux) {