Leave source list empty for Fuchsia targets. (#15337)

packages/flutter/BUILD.gn

diff --git a/packages/flutter/BUILD.gn b/packages/flutter/BUILD.gn
index bf4cff6..27f9245 100644
--- a/packages/flutter/BUILD.gn
+++ b/packages/flutter/BUILD.gn
@@ -7,22 +7,10 @@
 dart_library("flutter") {
   package_name = "flutter"
 
-  disable_analysis = true
+  # Can be left empty as analysis is disabled.
+  sources = []
 
-  sources = [
-    "animation.dart",
-    "cupertino.dart",
-    "foundation.dart",
-    "gestures.dart",
-    "material.dart",
-    "painting.dart",
-    "physics.dart",
-    "rendering.dart",
-    "scheduler.dart",
-    "semantics.dart",
-    "services.dart",
-    "widgets.dart",
-  ]
+  disable_analysis = true
 
   deps = [
     "//third_party/dart/third_party/pkg/intl",

packages/flutter_test/BUILD.gn

diff --git a/packages/flutter_test/BUILD.gn b/packages/flutter_test/BUILD.gn
index e606491..09c91aa 100644
--- a/packages/flutter_test/BUILD.gn
+++ b/packages/flutter_test/BUILD.gn
@@ -7,9 +7,8 @@
 dart_library("flutter_test") {
   package_name = "flutter_test"
 
-  sources = [
-    "flutter_test.dart",
-  ]
+  # Can be left empty as analysis is disabled.
+  sources = []
 
   disable_analysis = true
 

packages/flutter_tools/BUILD.gn

diff --git a/packages/flutter_tools/BUILD.gn b/packages/flutter_tools/BUILD.gn
index c64e626..a233fb7 100644
--- a/packages/flutter_tools/BUILD.gn
+++ b/packages/flutter_tools/BUILD.gn
@@ -8,10 +8,8 @@
 dart_library("flutter_tools") {
   package_name = "flutter_tools"
 
-  sources = [
-    "executable.dart",
-    "runner.dart",
-  ]
+  # Can be left empty as analysis is disabled.
+  sources = []
 
   disable_analysis = true