Add AssignmentSource to BlimpClientContextImpl

blimp/client/core/android/blimp_client_context_impl_android.h

Index: blimp/client/core/android/blimp_client_context_impl_android.h
diff --git a/blimp/client/core/android/blimp_client_context_impl_android.h b/blimp/client/core/android/blimp_client_context_impl_android.h
index e3cf8d40cdf2d5259eaa25f17371052f93c1b051..eb4a3b576ab95c397848c299654782526bbbe4c3 100644
--- a/blimp/client/core/android/blimp_client_context_impl_android.h
+++ b/blimp/client/core/android/blimp_client_context_impl_android.h
@@ -21,8 +21,11 @@ class BlimpClientContextImplAndroid : public BlimpClientContextImpl {
 
   // The |io_thread_task_runner| must be the task runner to use for IO
   // operations.
+  // The |file_thread_task_runner| must be the task runner to use for file
+  // operations.
   explicit BlimpClientContextImplAndroid(
-      scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner);
+      scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> file_thread_task_runner);
   ~BlimpClientContextImplAndroid() override;
 
   base::android::ScopedJavaLocalRef<jobject> GetJavaObject();
@@ -31,6 +34,10 @@ class BlimpClientContextImplAndroid : public BlimpClientContextImpl {
       JNIEnv* env,
       jobject jobj);
 
+ protected:
+  // BlimpClientContextImpl implementation.
+  GURL GetAssignerURL() override;
+
  private:
   base::android::ScopedJavaGlobalRef<jobject> java_obj_;