Add //google_apis/* to 'gn check'.

This fixed the remaining erros found by 'gn check', so we can enable it
on all bots.

Checked with the following command lines:

Linux
$ gn gen out-gn
$ gn check out-gn //google_apis/*

$ Android
$ gn gen out-gn-android --args='target_os="android"'
$ gn check out-android //google_apis/*

$ ChromeOS
$ gn gen out-gn-chromeos --args='host_os="chromeos"'
$ gn check out-gn-chromeos //google_apis/*

BUG=None
TEST=see above
R=dpranke@chromium.org
TBR=rogerta@chromium.org,zea@chromium.org

CQ_EXTRA_TRYBOTS=tryserver.chromium.linux:android_chromium_gn_compile_dbg,android_chromium_gn_compile_rel;tryserver.chromium.win:win8_chromium_gn_rel,win8_chromium_gn_dbg;tryserver.chromium.mac:mac_chromium_gn_rel,mac_chromium_gn_dbg

Review URL: https://codereview.chromium.org/970613002

Cr-Commit-Position: refs/heads/master@{#318645}

.gn

@@ -41,7 +41,7 @@ check_targets = [
 
   #"//extensions/*",  # Lots of errors.
   #"//gin/*",  # Easy.
-  #"//google_apis/*",  # Easy.
+  "//google_apis/*",
   "//google_update/*",
 
   #"//gpu/*",  # Lots of errors.

google_apis/BUILD.gn

@@ -185,6 +185,9 @@ source_set("test_support") {
     "//net:test_support",
   ]
 
+  deps = [
+    ":google_apis",
+  ]
   if (enable_extensions) {
     sources += [
       "drive/dummy_auth_service.cc",

google_apis/gcm/BUILD.gn

@@ -89,6 +89,7 @@ static_library("test_support") {
   ]
   deps = [
     "//base",
+    "//net",
     "//testing/gtest",
   ]
 }