[CodeHealth] Enable gn check for //ppapi/host:*

Fixed: 1158993
Change-Id: I516b5ba97913638a34dbbb078c59305ddb474d28
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2980612
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Vidhan Jain <vidhanj@google.com>
Cr-Commit-Position: refs/heads/master@{#894933}

.gn

@@ -68,7 +68,6 @@ no_check_targets = [
   "//headless:*",  # 167 errors
   "//native_client/src/trusted/service_runtime:*",  # 2 errors
   "//ppapi/cpp/private:*",  # 1 error
-  "//ppapi/host:*",  # 1 error
   "//ppapi/native_client/src/untrusted/pnacl_irt_shim:*",  # 197 errors
   "//ppapi/proxy:*",  # 31 errors
   "//ppapi/thunk:*",  # 1071 errors

ppapi/host/BUILD.gn

@@ -32,6 +32,7 @@ component("host") {
   deps = [
     "//base",
     "//media:shared_memory_support",
+    "//net",
     "//ppapi/c",
     "//ppapi/proxy:ipc",
     "//ppapi/shared_impl",