Put more files under the enable_service_discovery build flag.

chrome/browser/devtools/BUILD.gn

Index: chrome/browser/devtools/BUILD.gn
diff --git a/chrome/browser/devtools/BUILD.gn b/chrome/browser/devtools/BUILD.gn
index 17b2789cd81673d85f54608dbebf13299d4a8991..2b603823c31e2adf3e6221d304e55ce1c84b1f1c 100644
--- a/chrome/browser/devtools/BUILD.gn
+++ b/chrome/browser/devtools/BUILD.gn
@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 if (!is_android) {
+  import("//build/config/features.gni")
   import("//tools/grit/grit_rule.gni")
 }
 
@@ -93,8 +94,6 @@ static_library("devtools") {
       "device/android_device_manager.cc",
       "device/android_device_manager.h",
       "device/android_web_socket.cc",
-      "device/cast_device_provider.cc",
-      "device/cast_device_provider.h",
       "device/devtools_android_bridge.cc",
       "device/devtools_android_bridge.h",
       "device/port_forwarding_controller.cc",
@@ -109,14 +108,6 @@ static_library("devtools") {
       "device/usb/android_usb_socket.h",
       "device/usb/usb_device_provider.cc",
       "device/usb/usb_device_provider.h",
-      "device/webrtc/devtools_bridge_client.cc",
-      "device/webrtc/devtools_bridge_client.h",
-      "device/webrtc/devtools_bridge_instances_request.cc",
-      "device/webrtc/devtools_bridge_instances_request.h",
-      "device/webrtc/send_command_request.cc",
-      "device/webrtc/send_command_request.h",
-      "device/webrtc/webrtc_device_provider.cc",
-      "device/webrtc/webrtc_device_provider.h",
       "devtools_contents_resizing_strategy.cc",
       "devtools_contents_resizing_strategy.h",
       "devtools_embedder_message_dispatcher.cc",
@@ -142,6 +133,20 @@ static_library("devtools") {
       "remote_debugging_server.cc",
       "remote_debugging_server.h",
     ]
+    if (enable_service_discovery) {

[Vitaly Buka (NO REVIEWS), 2016/01/04 23:10:46]

I guess it's always enabled on platforms with devtools.

+      sources += [
+        "device/cast_device_provider.cc",
+        "device/cast_device_provider.h",
+        "device/webrtc/devtools_bridge_client.cc",
+        "device/webrtc/devtools_bridge_client.h",

[Vitaly Buka (NO REVIEWS), 2016/01/04 23:10:46]

Some of these files depend on gcd_api_flow.cc only. That file is under
local_discovery but it has nothing to do with it.
It just browser to server communication.

Plan was to make it wrapper that picks local vs server protocol inside. But this
is not going to happen any more. So best place for gcd_api_flow.cc is probably
components/cloud_devices/ 

I started to that as part of crbug.com/551631

Technically with current state of the code your CL is still correct.
Can you wait until I move that file so you can avoid changing webrtc stuff?

+        "device/webrtc/devtools_bridge_instances_request.cc",
+        "device/webrtc/devtools_bridge_instances_request.h",
+        "device/webrtc/send_command_request.cc",

[Vitaly Buka (NO REVIEWS), 2016/01/05 01:18:13]

Actually this code is obsolete and going away:
https://codereview.chromium.org/1560583002/

[Lei Zhang, 2016/01/05 02:36:10]

I'll wait for that to land and see what we end up with here. No rush.

+        "device/webrtc/send_command_request.h",
+        "device/webrtc/webrtc_device_provider.cc",
+        "device/webrtc/webrtc_device_provider.h",
+      ]
+    }
   }
 }