Fix up build/test issues when building on or off of mac (flutter#148)

Author: dnfield

impeller/BUILD.gn

@@ -18,7 +18,11 @@ config("impeller_public_config") {
   }
 
   if (is_win) {
-    defines += [ "_USE_MATH_DEFINES" ]
+    defines += [
+      "_USE_MATH_DEFINES",
+      # TODO(dnfield): https://github.com/flutter/flutter/issues/50053
+      "_SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING",
+    ]
   }
 }
 
@@ -50,7 +54,6 @@ executable("impeller_unittests") {
     "base:base_unittests",
     "blobcat:blobcat_unittests",
     "compiler:compiler_unittests",
-    "fixtures",
     "geometry:geometry_unittests",
 
     # FML depends on the Dart VM for tracing and getting the current
@@ -63,6 +66,7 @@ executable("impeller_unittests") {
       "aiks:aiks_unittests",
       "display_list:display_list_unittests",
       "entity:entity_unittests",
+      "fixtures",
       "image:image_unittests",
       "playground",
       "renderer:renderer_unittests",

impeller/compiler/utilities.cc

@@ -4,9 +4,9 @@
 
 #include "impeller/compiler/utilities.h"
 
+#include <cctype>
 #include <filesystem>
 #include <sstream>
-#include <string>
 
 namespace impeller {
 namespace compiler {

impeller/display_list/display_list_unittests.cc

@@ -176,7 +176,7 @@ TEST_P(DisplayListTest, StrokedPathsDrawCorrectly) {
   ASSERT_TRUE(OpenPlaygroundHere(builder.Build()));
 }
 
-TEST_F(DisplayListTest, CanDrawWithMaskBlur) {
+TEST_P(DisplayListTest, CanDrawWithMaskBlur) {
   auto texture = CreateTextureForFixture("embarcadero.jpg");
   flutter::DisplayListBuilder builder;
 

impeller/playground/playground.cc

@@ -37,7 +37,7 @@ std::string PlaygroundBackendToString(PlaygroundBackend backend) {
 Playground::Playground()
     : impl_(PlaygroundImpl::Create(GetParam())),
       renderer_(impl_->CreateContext()),
-      is_valid_(Playground::is_enabled() && renderer_.IsValid()) {}
+      is_valid_(renderer_.IsValid()) {}
 
 Playground::~Playground() = default;