Remove system_wrappers dep from field_trial_default and metrics_default.

field_trial_default and metrics_default don't use system_wrappers and
don't need to depend on it. The dependency on field_trial_default was
added in libjingle in crrev.com/356135 and that broke compilation of
libjingle for NaCl with GN because system_wrappers currently doesn't
compile for NaCl.

TBR=niklas.enbom@webrtc.org

Review URL: https://codereview.webrtc.org/1412003007

Cr-Commit-Position: refs/heads/master@{#10495}

webrtc/system_wrappers/BUILD.gn

@@ -179,10 +179,6 @@ source_set("field_trial_default") {
 
   configs += [ "..:common_config" ]
   public_configs = [ "..:common_inherited_config" ]
-
-  deps = [
-    ":system_wrappers",
-  ]
 }
 
 source_set("metrics_default") {
@@ -192,10 +188,6 @@ source_set("metrics_default") {
 
   configs += [ "..:common_config" ]
   public_configs = [ "..:common_inherited_config" ]
-
-  deps = [
-    ":system_wrappers",
-  ]
 }
 
 source_set("system_wrappers_default") {
@@ -203,6 +195,7 @@ source_set("system_wrappers_default") {
   public_configs = [ "..:common_inherited_config" ]
 
   deps = [
+    ":system_wrappers",
     ":field_trial_default",
     ":metrics_default",
   ]

webrtc/system_wrappers/system_wrappers.gyp

@@ -206,13 +206,11 @@
       'sources': [
         'source/metrics_default.cc',
       ],
-      'dependencies': [
-        'system_wrappers',
-      ]
     }, {
       'target_name': 'system_wrappers_default',
       'type': 'static_library',
       'dependencies': [
+        'system_wrappers',
         'field_trial_default',
         'metrics_default',
       ]