SkQP: slim deps.  Also skia_enable_fontmgr_empty

Change-Id: I24ee2fb3a4a4ca03a60ee2f1a90e022825eee409
Reviewed-on: https://skia-review.googlesource.com/101820
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 5514093..110cb0e 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -37,6 +37,7 @@
   skia_enable_discrete_gpu = true
   skia_enable_effects = true
   skia_enable_flutter_defines = false
+  skia_enable_fontmgr_empty = false
   skia_enable_gpu = true
   skia_enable_pdf = true
   skia_enable_spirv_validation = is_skia_dev_build && is_debug
@@ -391,6 +392,13 @@
   ]
 }
 
+optional("fontmgr_empty") {
+  enabled = skia_enable_fontmgr_empty
+  sources = [
+    "src/ports/SkFontMgr_empty_factory.cpp",
+  ]
+}
+
 optional("fontmgr_fontconfig") {
   enabled = skia_use_freetype && skia_use_fontconfig
 
@@ -755,6 +763,7 @@
     ":effects",
     ":fontmgr_android",
     ":fontmgr_custom",
+    ":fontmgr_empty",
     ":fontmgr_fontconfig",
     ":fontmgr_fuchsia",
     ":gpu",
@@ -1309,13 +1318,15 @@
     }
     deps = [
       ":experimental_sksg",
-      ":experimental_svg_model",
       ":flags",
       ":skia",
       ":tool_utils",
       "//third_party/libpng",
       "//third_party/zlib",
     ]
+    if (skia_use_expat) {
+      deps += [ ":experimental_svg_model" ]
+    }
     public_deps = [
       ":gpu_tool_utils",  # Test.h #includes headers from this target.
     ]