Gets gn check to execute cleanly in mojo/common

This one is trickier. I'm changing mojo/common:common_base to be a
source_set. Here's why. When I add the necessary deps, in particular
    "//third_party/mojo/src/mojo/public/cpp/bindings:bindings",
then I get link errors for the environment, eg
gen/third_party/mojo/src/mojo/public/interfaces/bindings/interface_control_messages.mojom.cc:719: error: undefined reference to 'mojo::Environment::GetDefaultLogger()'
These symbols are in //mojo/environment. If I add //mojo/environment
to the list of deps for common_base I end up with a cycle as
environment depends upon common_base. By changing to source_set
common_base isn't linked and everyone is happy.

As a result of this I had to consolidate //mojo/environment into a single source set.

BUG=none
TEST=none
R=ben@chromium.org

Review URL: https://codereview.chromium.org/1256593003

Cr-Commit-Position: refs/heads/master@{#340527}

3 files changed, 16 insertions, 32 deletions

diff --git a/.gn b/.gn
index cfebd67..8068622 100644
--- a/.gn
+++ b/.gn
@@ -75,9 +75,7 @@ check_targets = [
   "mojo/application/*",
   "mojo/build/*",
   "mojo/cc/*",
-
-  # TODO(sky): resolve this.
-  # "mojo/common/*",
+  "mojo/common/*",
   "mojo/converters/*",
   "mojo/environment/*",
 
diff --git a/mojo/common/BUILD.gn b/mojo/common/BUILD.gn
index 1548798..6499e72 100644
--- a/mojo/common/BUILD.gn
+++ b/mojo/common/BUILD.gn
@@ -12,7 +12,7 @@ group("common") {
 }
 
 # GYP version: mojo/mojo_base.gyp:mojo_common_lib
-component("common_base") {
+source_set("common_base") {
   output_name = "mojo_common_lib"
 
   sources = [
@@ -40,6 +40,8 @@ component("common_base") {
     "//base",
     "//base/third_party/dynamic_annotations",
     "//third_party/mojo/src/mojo/public/c/system:for_component",
+    "//third_party/mojo/src/mojo/public/cpp/bindings:bindings",
+    "//third_party/mojo/src/mojo/public/cpp/system:system",
   ]
 }
 
diff --git a/mojo/environment/BUILD.gn b/mojo/environment/BUILD.gn
index 9621dfb..6b6f6eb 100644
--- a/mojo/environment/BUILD.gn
+++ b/mojo/environment/BUILD.gn
@@ -7,6 +7,14 @@ source_set("chromium") {
   output_name = "mojo_environment_chromium"
 
   sources = [
+    "default_async_waiter_impl.cc",
+    "default_async_waiter_impl.h",
+    "default_logger_impl.cc",
+    "default_logger_impl.h",
+    "default_run_loop_impl.cc",
+    "default_run_loop_impl.h",
+    "default_task_tracker_impl.cc",
+    "default_task_tracker_impl.h",
     "environment.cc",
 
     # TODO(vtl): This is kind of ugly. (See TODO in logging.h.)
@@ -19,43 +27,19 @@ source_set("chromium") {
     "//third_party/mojo/src/mojo/public/cpp/environment/task_tracker.h",
   ]
 
-  public_deps = [
-    ":chromium_impl",
-  ]
-
   deps = [
+    "//base",
+    "//base/third_party/dynamic_annotations",
+    "//mojo/common:common_base",
+    "//third_party/mojo/src/mojo/public/cpp/environment:environment",
     "//third_party/mojo/src/mojo/public/c/environment",
     "//third_party/mojo/src/mojo/public/cpp/bindings:callback",
     "//third_party/mojo/src/mojo/public/cpp/environment",
     "//third_party/mojo/src/mojo/public/cpp/system",
   ]
-}
-
-# GYP version: mojo_base.gyp:mojo_environment_chromium_impl
-component("chromium_impl") {
-  output_name = "mojo_environment_impl"
-  visibility = [ "//mojo/*" ]
-
-  sources = [
-    "default_async_waiter_impl.cc",
-    "default_async_waiter_impl.h",
-    "default_logger_impl.cc",
-    "default_logger_impl.h",
-    "default_run_loop_impl.cc",
-    "default_run_loop_impl.h",
-    "default_task_tracker_impl.cc",
-    "default_task_tracker_impl.h",
-  ]
 
   defines = [ "MOJO_ENVIRONMENT_IMPL_IMPLEMENTATION" ]
 
   public_configs =
       [ "//third_party/mojo/src/mojo/public/build/config:mojo_sdk" ]
-
-  deps = [
-    "//base",
-    "//base/third_party/dynamic_annotations",
-    "//mojo/common:common_base",
-    "//third_party/mojo/src/mojo/public/cpp/environment:environment",
-  ]
 }