diff --git a/BUILD.gn b/BUILD.gn
index d0127988af2..4fcf8040169 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/ui.gni")
 import("//tools/grit/grit_rule.gni")
 
 group("sky") {
@@ -12,9 +13,15 @@ group("sky") {
     "//sky/engine/platform:platform_unittests",
     "//sky/engine/web:sky_unittests",
     "//sky/engine/wtf:unittests",
-    "//sky/tools/debugger",
-    "//sky/tools/tester",
     "//sky/viewer",
-    "//third_party/mesa:osmesa",
   ]
+  if (use_aura) {
+    deps += [
+      "//sky/tools/debugger",
+      "//sky/tools/tester",
+    ]
+  }
+  if (!is_android) {
+    deps += [ "//third_party/mesa:osmesa" ]
+  }
 }
diff --git a/engine/platform/BUILD.gn b/engine/platform/BUILD.gn
index 477790270ea..5f2ad24f310 100644
--- a/engine/platform/BUILD.gn
+++ b/engine/platform/BUILD.gn
@@ -5,7 +5,6 @@
 import("//build/config/ui.gni")
 import("//sky/engine/build/scripts/scripts.gni")
 import("//sky/engine/config.gni")
-import("//third_party/yasm/yasm_assemble.gni")
 
 # Most targets in this file are private actions so use that as the default.
 visibility = [":*"]
@@ -754,16 +753,12 @@ component("platform") {
   }
 }
 
+if (cpu_arch == "x86" || cpu_arch == "x64") {
+
+import("//third_party/yasm/yasm_assemble.gni")
+
 yasm_assemble("heap_asm_stubs") {
-  if (cpu_arch == "x86" || cpu_arch == "x64") {
-    sources = [ "heap/asm/SaveRegisters_x86.asm" ]
-  } else if (cpu_arch == "arm") {
-    sources = [ "heap/asm/SaveRegisters_arm.S" ]
-  } else if (cpu_arch == "arm64") {
-    sources = [ "heap/asm/SaveRegisters_arm64.S" ]
-  } else if (cpu_arch == "mipsel") {
-    sources = [ "heap/asm/SaveRegisters_mips.S" ]
-  }
+  sources = [ "heap/asm/SaveRegisters_x86.asm" ]
 
   yasm_flags = []
   if (is_mac) {
@@ -779,11 +774,27 @@ yasm_assemble("heap_asm_stubs") {
     }
   } else if (cpu_arch == "x86") {
     yasm_flags += [ "-DIA32=1" ]
-  } else if (cpu_arch == "arm") {
-    yasm_flags += [ "-DARM=1" ]
   }
 }
 
+} else { # cpu_arch == "x86" || cpu_arch == "x64"
+
+source_set("heap_asm_stubs") {
+  if (cpu_arch == "arm") {
+    sources = [ "heap/asm/SaveRegisters_arm.S" ]
+  } else if (cpu_arch == "arm64") {
+    sources = [ "heap/asm/SaveRegisters_arm64.S" ]
+  } else if (cpu_arch == "mipsel") {
+    sources = [ "heap/asm/SaveRegisters_mips.S" ]
+  }
+
+  if (cpu_arch == "arm") {
+    defines = [ "ARM=1" ]
+  }
+}
+
+}
+
 test("platform_unittests") {
   visibility += ["//sky/*"]
   output_name = "sky_platform_unittests"
diff --git a/engine/public/BUILD.gn b/engine/public/BUILD.gn
index 4b82ed10206..8013fda08fc 100644
--- a/engine/public/BUILD.gn
+++ b/engine/public/BUILD.gn
@@ -4,8 +4,6 @@
 
 import("//tools/grit/grit_rule.gni")
 
-if (!is_android) {
-
 group("blink") {
   deps = [
     ":sky_headers",
@@ -31,8 +29,6 @@ group("test_support") {
   ]
 }
 
-}  # !is_android
-
 config("sky_headers_config") {
   include_dirs = [ ".." ]
 }