Move blimp AssignmentSource to core

blimp/client/core/BUILD.gn

 # Copyright 2016 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.
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
 }
 
 declare_args() {
@@ skipping 87 matching lines @@
 
   sources = [
     "blimp_client_context_impl_unittest.cc",
     "blimp_contents_impl_unittest.cc",
     "blimp_navigation_controller_impl_unittest.cc",
   ]
 
   deps = [
     ":core",
     "//base",
+    "//blimp/client/core/session:unit_tests",
     "//blimp/client/public:public_headers",
     "//blimp/client/test",
     "//testing/gtest",
     "//url",
   ]
 }
 
 source_set("switches") {
   visibility = [
     "//blimp/client/*",
@@ skipping 71 matching lines @@
   generate_jni("dummy_core_jni_headers") {
     visibility = [ ":*" ]
 
     sources = [
       "android/java/src/org/chromium/blimp/core/DummyBlimpClientContext.java",
     ]
 
     jni_package = "blimp/client/core"
   }
 }