Remove all uses of the redundant flutter_root variable. (flutter#16311)

This was only necessary when the Engine had to build in multiple buildroots
where the sources where checked out at different paths relative to the
buildroot. This is no longer the case and there are already cases GN rules
have been written that mix and match variable usage with the direct
specification of the path to the Flutter sources relative to the sole buildroot.

BUILD.gn

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("$flutter_root/common/config.gni")
+import("//flutter/common/config.gni")
 
 if (is_fuchsia) {
   import("//build/fuchsia/sdk.gni")
@@ -21,41 +21,41 @@ group("flutter") {
 
   if (!(is_fuchsia && using_fuchsia_sdk)) {
     public_deps += [
-      "$flutter_root/lib/snapshot:generate_snapshot_bin",
-      "$flutter_root/lib/snapshot:kernel_platform_files",
+      "//flutter/lib/snapshot:generate_snapshot_bin",
+      "//flutter/lib/snapshot:kernel_platform_files",
     ]
   }
 
   public_deps += [
-    "$flutter_root/shell/platform/embedder:flutter_engine",
-    "$flutter_root/sky",
+    "//flutter/shell/platform/embedder:flutter_engine",
+    "//flutter/sky",
   ]
 
   if (current_toolchain == host_toolchain) {
-    public_deps += [ "$flutter_root/tools/font-subset" ]
+    public_deps += [ "//flutter/tools/font-subset" ]
   }
 
   if (current_toolchain == host_toolchain) {
-    public_deps += [ "$flutter_root/shell/testing" ]
+    public_deps += [ "//flutter/shell/testing" ]
     public_deps += [ "//flutter/tools/const_finder" ]
   }
 
   if (is_fuchsia && using_fuchsia_sdk) {
     public_deps += [
-      "$flutter_root/shell/platform/fuchsia",
-      "$flutter_root/shell/testing($host_toolchain)",
+      "//flutter/shell/platform/fuchsia",
+      "//flutter/shell/testing($host_toolchain)",
     ]
   }
 
   if (!is_fuchsia && !is_fuchsia_host) {
     if (current_toolchain == host_toolchain) {
       public_deps += [
-        "$flutter_root/flutter_frontend_server:frontend_server",
+        "//flutter/flutter_frontend_server:frontend_server",
         "//third_party/dart:create_sdk",
       ]
 
       if (full_dart_sdk) {
-        public_deps += [ "$flutter_root/web_sdk" ]
+        public_deps += [ "//flutter/web_sdk" ]
       }
     }
   }
@@ -64,36 +64,36 @@ group("flutter") {
   if (current_toolchain == host_toolchain) {
     if (is_mac) {
       public_deps += [
-        "$flutter_root/shell/platform/darwin:flutter_channels_unittests",
-        "$flutter_root/shell/platform/darwin/macos:flutter_desktop_darwin_unittests",
+        "//flutter/shell/platform/darwin:flutter_channels_unittests",
+        "//flutter/shell/platform/darwin/macos:flutter_desktop_darwin_unittests",
       ]
     }
 
     public_deps += [
-      "$flutter_root/flow:flow_unittests",
-      "$flutter_root/fml:fml_unittests",
-      "$flutter_root/lib/ui:ui_unittests",
-      "$flutter_root/runtime:runtime_unittests",
-      "$flutter_root/shell/common:shell_unittests",
-      "$flutter_root/shell/platform/common/cpp/client_wrapper:client_wrapper_unittests",
-      "$flutter_root/shell/platform/embedder:embedder_unittests",
-      "$flutter_root/shell/platform/glfw/client_wrapper:client_wrapper_glfw_unittests",
-      "$flutter_root/testing:testing_unittests",
-      "$flutter_root/third_party/txt:txt_unittests",
+      "//flutter/flow:flow_unittests",
+      "//flutter/fml:fml_unittests",
+      "//flutter/lib/ui:ui_unittests",
+      "//flutter/runtime:runtime_unittests",
+      "//flutter/shell/common:shell_unittests",
+      "//flutter/shell/platform/common/cpp/client_wrapper:client_wrapper_unittests",
+      "//flutter/shell/platform/embedder:embedder_unittests",
+      "//flutter/shell/platform/glfw/client_wrapper:client_wrapper_glfw_unittests",
+      "//flutter/testing:testing_unittests",
+      "//flutter/third_party/txt:txt_unittests",
     ]
 
     if (is_win) {
       public_deps += [
-        "$flutter_root/shell/platform/windows:flutter_windows_unittests",
-        "$flutter_root/shell/platform/windows/client_wrapper:client_wrapper_windows_unittests",
+        "//flutter/shell/platform/windows:flutter_windows_unittests",
+        "//flutter/shell/platform/windows/client_wrapper:client_wrapper_windows_unittests",
       ]
     }
 
     if (!is_win) {
       public_deps += [
-        "$flutter_root/fml:fml_benchmarks",
-        "$flutter_root/shell/common:shell_benchmarks",
-        "$flutter_root/third_party/txt:txt_benchmarks",
+        "//flutter/fml:fml_benchmarks",
+        "//flutter/shell/common:shell_benchmarks",
+        "//flutter/third_party/txt:txt_benchmarks",
       ]
     }
   }
@@ -111,7 +111,7 @@ config("config") {
 config("export_dynamic_symbols") {
   if (is_linux || is_fuchsia) {
     inputs = [
-      "$flutter_root/common/exported_symbols.sym",
+      "//flutter/common/exported_symbols.sym",
     ]
     ldflags = [ "-Wl,--dynamic-list=" + rebase_path(inputs[0], root_build_dir) ]
   }
@@ -121,7 +121,7 @@ group("dist") {
   testonly = true
 
   deps = [
-    "$flutter_root/sky/dist",
+    "//flutter/sky/dist",
   ]
 }
 
@@ -133,9 +133,9 @@ if (is_fuchsia) {
     testonly = true
 
     deps = [
-      "$flutter_root/flow:flow_tests",
-      "$flutter_root/fml:fml_tests",
-      "$flutter_root/shell/platform/fuchsia/flutter:flutter_runner_tests",
+      "//flutter/flow:flow_tests",
+      "//flutter/fml:fml_tests",
+      "//flutter/shell/platform/fuchsia/flutter:flutter_runner_tests",
     ]
   }
 }

assets/BUILD.gn

@@ -12,9 +12,9 @@ source_set("assets") {
   ]
 
   deps = [
-    "$flutter_root/common",
-    "$flutter_root/fml",
+    "//flutter/common",
+    "//flutter/fml",
   ]
 
-  public_configs = [ "$flutter_root:config" ]
+  public_configs = [ "//flutter:config" ]
 }

benchmarking/BUILD.gn

@@ -15,12 +15,12 @@ source_set("benchmarking") {
   ]
 
   public_deps = [
-    "$flutter_root/fml",
+    "//flutter/fml",
     "//third_party/benchmark",
   ]
 
   public_configs = [
-    "$flutter_root:config",
+    "//flutter:config",
     ":benchmark_config",
   ]
 }

build/dart/rules.gni

@@ -44,8 +44,7 @@ template("dart_pkg_helper") {
       sdk_ext_mappings += invoker.sdk_ext_mappings
     }
 
-    script =
-        rebase_path("$flutter_root/build/dart/tools/dart_pkg.py", ".", "//")
+    script = rebase_path("//flutter/build/dart/tools/dart_pkg.py", ".", "//")
 
     entrypoints = []
     if (defined(invoker.apps)) {
@@ -62,8 +61,7 @@ template("dart_pkg_helper") {
     if (defined(invoker.sources)) {
       sources += invoker.sources
     } else if (defined(invoker.pkg_dir)) {
-      list_script =
-          rebase_path("$flutter_root/build/dart/tools/ls.py", ".", "//")
+      list_script = rebase_path("//flutter/build/dart/tools/ls.py", ".", "//")
       extra_flags += [ "--read_only" ]
       ls_sources = exec_script(list_script,
                                [
@@ -115,9 +113,7 @@ template("dart_pkg") {
     pubspec_yaml_path = rebase_path("pubspec.yaml")
   }
   dart_package_name_script =
-      rebase_path("$flutter_root/build/dart/tools/dart_package_name.py",
-                  ".",
-                  "//")
+      rebase_path("//flutter/build/dart/tools/dart_package_name.py", ".", "//")
   dart_package_name = exec_script(dart_package_name_script,
                                   [
                                     "--pubspec",

common/BUILD.gn

@@ -17,11 +17,11 @@ source_set("common") {
   ]
 
   deps = [
-    "$flutter_root/fml",
+    "//flutter/fml",
   ]
 
   public_configs = [
     ":flutter_config",
-    "$flutter_root:config",
+    "//flutter:config",
   ]
 }

flow/BUILD.gn

@@ -4,9 +4,9 @@
 
 if (is_fuchsia) {
   import("//build/fuchsia/sdk.gni")
-  import("$flutter_root/tools/fuchsia/fuchsia_archive.gni")
+  import("//flutter/tools/fuchsia/fuchsia_archive.gni")
 }
-import("$flutter_root/testing/testing.gni")
+import("//flutter/testing/testing.gni")
 
 source_set("flow") {
   sources = [
@@ -64,13 +64,13 @@ source_set("flow") {
     "texture.h",
   ]
 
-  public_configs = [ "$flutter_root:config" ]
+  public_configs = [ "//flutter:config" ]
 
   public_deps = []
 
   deps = [
-    "$flutter_root/common",
-    "$flutter_root/fml",
+    "//flutter/common",
+    "//flutter/fml",
     "//third_party/skia",
   ]
 
@@ -119,7 +119,7 @@ source_set("flow_testing") {
 
   public_deps = [
     ":flow",
-    "$flutter_root/testing:skia",
+    "//flutter/testing:skia",
     "//third_party/googletest:gtest",
   ]
 }
@@ -160,9 +160,9 @@ executable("flow_unittests") {
     ":flow",
     ":flow_fixtures",
     ":flow_testing",
-    "$flutter_root/fml",
-    "$flutter_root/testing:skia",
-    "$flutter_root/testing:testing_lib",
+    "//flutter/fml",
+    "//flutter/testing:skia",
+    "//flutter/testing:testing_lib",
     "//third_party/dart/runtime:libdart_jit",  # for tracing
     "//third_party/googletest:gtest",
     "//third_party/skia",
@@ -181,23 +181,23 @@ if (is_fuchsia) {
 
     libraries = common_libs
 
-    meta_dir = "$flutter_root/testing/fuchsia/meta"
+    meta_dir = "//flutter/testing/fuchsia/meta"
     cmx_file = "$meta_dir/fuchsia_test.cmx"
 
     resources = [
       {
         path = rebase_path(
-                "$flutter_root/testing/resources/performance_overlay_gold_60fps.png")
+                "//flutter/testing/resources/performance_overlay_gold_60fps.png")
         dest = "flutter/testing/resources/performance_overlay_gold_60fps.png"
       },
       {
         path = rebase_path(
-                "$flutter_root/testing/resources/performance_overlay_gold_90fps.png")
+                "//flutter/testing/resources/performance_overlay_gold_90fps.png")
         dest = "flutter/testing/resources/performance_overlay_gold_90fps.png"
       },
       {
         path = rebase_path(
-                "$flutter_root/testing/resources/performance_overlay_gold_120fps.png")
+                "//flutter/testing/resources/performance_overlay_gold_120fps.png")
         dest = "flutter/testing/resources/performance_overlay_gold_120fps.png"
       },
     ]

flutter_frontend_server/BUILD.gn

@@ -68,7 +68,7 @@ application_snapshot("frontend_server") {
   main_dart = "bin/starter.dart"
   deps = [
     ":package_incremental_compiler",
-    "$flutter_root/lib/snapshot:kernel_platform_files",
+    "//flutter/lib/snapshot:kernel_platform_files",
   ]
   dot_packages = rebase_path(".packages")
   flutter_patched_sdk = rebase_path("$root_out_dir/flutter_patched_sdk")
@@ -84,7 +84,7 @@ application_snapshot("frontend_server") {
 # For flutter/flutter#36738 we make the source files available so that
 # we can generate a local frontend_server snapshot in the tools cache.
 action("package_incremental_compiler") {
-  script = "$flutter_root/flutter_frontend_server/package_incremental.py"
+  script = "//flutter/flutter_frontend_server/package_incremental.py"
 
   inputs = frontend_server_files
 
@@ -101,6 +101,6 @@ action("package_incremental_compiler") {
   args = [
     "--input-root=" + rebase_path("//third_party/dart/pkg"),
     "--output-root=" + rebase_path("$root_gen_dir/dart-pkg"),
-    "--frontend-server=" + rebase_path("$flutter_root"),
+    "--frontend-server=" + rebase_path("//flutter"),
   ]
 }

fml/BUILD.gn

@@ -4,9 +4,9 @@
 
 if (is_fuchsia) {
   import("//build/fuchsia/sdk.gni")
-  import("$flutter_root/tools/fuchsia/fuchsia_archive.gni")
+  import("//flutter/tools/fuchsia/fuchsia_archive.gni")
 }
-import("$flutter_root/testing/testing.gni")
+import("//flutter/testing/testing.gni")
 
 source_set("fml") {
   sources = [
@@ -96,8 +96,8 @@ source_set("fml") {
   configs += [ "//third_party/icu:icu_config" ]
 
   public_configs = [
-    "$flutter_root:config",
-    "$flutter_root/common:flutter_config",
+    "//flutter:config",
+    "//flutter/common:flutter_config",
   ]
 
   libs = []
@@ -249,10 +249,10 @@ executable("fml_unittests") {
 
   deps = [
     ":fml_fixtures",
-    "$flutter_root/fml",
-    "$flutter_root/fml/dart",
-    "$flutter_root/runtime:libdart",
-    "$flutter_root/testing",
+    "//flutter/fml",
+    "//flutter/fml/dart",
+    "//flutter/runtime:libdart",
+    "//flutter/testing",
   ]
 
   if (is_fuchsia && using_fuchsia_sdk) {
@@ -278,8 +278,8 @@ executable("fml_benchmarks") {
   ]
 
   deps = [
-    "$flutter_root/benchmarking",
-    "$flutter_root/fml",
-    "$flutter_root/runtime:libdart",
+    "//flutter/benchmarking",
+    "//flutter/fml",
+    "//flutter/runtime:libdart",
   ]
 }

fml/dart/BUILD.gn

@@ -12,8 +12,8 @@ source_set("dart") {
   ]
 
   public_deps = [
-    "$flutter_root/fml",
-    "$flutter_root/runtime:libdart",
-    "$flutter_root/third_party/tonic",
+    "//flutter/fml",
+    "//flutter/runtime:libdart",
+    "//flutter/third_party/tonic",
   ]
 }