Hook up content/browser compile in GN build.

BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 17 matching lines @@
     "//components/navigation_metrics",
     "//components/onc",
     "//components/os_crypt",
     "//components/query_parser",
     "//components/resources:components_resources",
     "//components/startup_metric_utils",
     "//components/tracing",
     "//components/translate:translate_core_browser",
     "//components/translate:translate_core_common",
     "//components/url_matcher",
-    #"//content/public/browser",  # Exists but doesn't build yet.
+    "//content/public/browser",
     "//content/public/child",
     "//content/public/common",
     "//content/public/renderer",
     "//content/browser/service_worker:database_proto",
     "//content/browser/speech/proto",
     "//crypto",
     "//extensions/common/api:extensions_api",
     "//dbus",
     "//device/usb",
     "//gin",
@@ skipping 74 matching lines @@
   }
 
   if (cpu_arch == "x86" || cpu_arch == "x64") {
     # YASM is x86/x64 only.
     deps += [ "//third_party/yasm($host_toolchain)" ]
   }
 
   if (is_android) {
     deps -= [
       "//cc",
+      "//content/public/browser",
       "//content/public/common",
       "//content/public/renderer",
       "//dbus",
       "//extensions/common/api:extensions_api",
       "//pdf",  # Not compiled on Android in GYP yet, either.
       "//ppapi:ppapi_c",
       "//sandbox",
       "//third_party/libusb",
 
       # Seems to not be compiled on Android. Otherwise it will need a config.h.
@@ skipping 15 matching lines @@
     ]
   }
 
   if (use_ozone) {
     deps += [
       "//ui/events/ozone:events_ozone",
       "//ui/events/ozone:events_ozone_evdev",
     ]
   }
 }