Move DevToolsNetLogObserver to c/b/loader and create stub of network service interface

content/browser/loader/DEPS

 # The core loading code in this directory is being transitioned into a separate
 # Mojo networking service. See http://crbug.com/598073. The first stage is to
 # decouple the code that will be moved from the rest of content. These rules
 # help ensure that we don't add more includes, and can progressively reduce the
 # code's dependencies.
 #
 # For each file, the first section shows includes that are allowed (i.e. because
 # they are for files that will be moving as well). The second section, separated
 # by a comment, lists files that we will have to decouple.
 specific_include_rules = {
   "async_resource_handler\.(cc|h)": [
     "-content",
     "+content/browser/loader/async_resource_handler.h",
+    "+content/browser/loader/netlog_observer.h",
     "+content/browser/loader/resource_buffer.h",
     "+content/browser/loader/resource_dispatcher_host_impl.h",
     "+content/browser/loader/resource_handler.h",
     "+content/browser/loader/resource_message_delegate.h",
     "+content/browser/loader/resource_message_filter.h",
     "+content/browser/loader/resource_request_info_impl.h",
     "+content/common/content_export.h",
     "+content/public/browser/resource_dispatcher_host_delegate.h",
     "+content/public/common/resource_response.h",
 
     # TODO: these all have to be removed.
-    "+content/browser/devtools/devtools_netlog_observer.h",
     "+content/browser/host_zoom_map_impl.h",
     "+content/browser/resource_context_impl.h",
     "+content/public/common/content_features.h",
 
     # TODO: To be replaced by mojo.
     "+content/common/resource_messages.h",
     "+content/common/view_messages.h",
   ],
   "async_revalidation_driver\.(cc|h)": [
     "-content",
@@ skipping 33 matching lines @@
   ],
   "global_routing_id\.h": [
     "-content",
   ],
   "layered_resource_handler\.(cc|h)": [
     "-content",
     "+content/browser/loader/layered_resource_handler.h",
     "+content/browser/loader/resource_handler.h",
     "+content/common/content_export.h",
   ],
+  "netlog_observer\.(cc|h)": [
+    "-content",
+    "+content/browser/loader/netlog_observer.h",
+    "+content/browser/loader/resource_request_info_impl.h",
+    "+content/public/common/resource_response.h",
+
+    # TODO: These all have to be removed.
+    "+content/public/browser/browser_thread.h",  # Only for DCHECK.
+    "+content/public/browser/content_browser_client.h",  # To get NetLog.
+    "+content/public/common/resource_devtools_info.h",
+  ],
   "power_save_block_resource_throttle\.(cc|h)": [
     "-content",
     "+content/browser/loader/power_save_block_resource_throttle.h",
     "+content/public/browser/resource_throttle.h",
 
     # TODO: these all have to be removed.
     "+content/public/browser/power_save_blocker.h",
   ],
   "resource_dispatcher_host_impl\.(cc|h)": [
     "-content",
@@ skipping 156 matching lines @@
     "+content/browser/loader/resource_scheduler.h",
     "+content/browser/loader/resource_scheduler_filter.h",
 
     # TODO: To be replaced by mojo.
     "+content/common/frame_messages.h",
     "+content/common/view_messages.h",
     "+content/public/browser/browser_message_filter.h",
   ],
   "sync_resource_handler\.(cc|h)": [
     "-content",
+    "+content/browser/loader/netlog_observer.h",
     "+content/browser/loader/resource_dispatcher_host_impl.h",
     "+content/browser/loader/resource_handler.h",
     "+content/browser/loader/resource_message_filter.h",
     "+content/browser/loader/resource_request_info_impl.h",
     "+content/browser/loader/sync_resource_handler.h",
     "+content/public/browser/resource_dispatcher_host_delegate.h",
     "+content/public/browser/resource_request_info.h",
     "+content/public/common/resource_response.h",
 
-    # TODO: These all have to be removed.
-    "+content/browser/devtools/devtools_netlog_observer.h",
 
     # TODO: To be replaced by mojo.
     "+content/common/resource_messages.h",
   ],
 }