Reland "Revert "custom typeface""

This reverts commit 61642b3.

Reason for revert: ../../src/utils/SkCustomTypeface.cpp(179,20): error: cannot decompose this type; 'std::tuple_size<const SkPoint>::value' is not a valid integral constant expression

Original change's description:
> Revert "Revert "custom typeface""
> 
> Fix: implement onComputeBounds() and generateFontMetrics()
> 
> This reverts commit 0066ade.
> 
> Change-Id: Idb59336a3d201bb97e494ee0e0bb189e0a7186f1
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/288536
> Commit-Queue: Mike Reed <reed@google.com>
> Reviewed-by: Ben Wagner <bungeman@google.com>

TBR=bungeman@google.com,reed@google.com

# Not skipping CQ checks because this is a reland.

Change-Id: I6845bb96a00a0c9ee54704a4c299556cc32e6438
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/288557
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

gn/gm.gni

@@ -378,7 +378,6 @@ gm_sources = [
   "$_gm/trickycubicstrokes.cpp",
   "$_gm/typeface.cpp",
   "$_gm/unpremul.cpp",
-  "$_gm/userfont.cpp",
   "$_gm/variedtext.cpp",
   "$_gm/verifiers/gmverifier.cpp",
   "$_gm/vertices.cpp",

gn/utils.gni

@@ -12,7 +12,6 @@ skia_utils_public = [
   "$_include/utils/SkBase64.h",
   "$_include/utils/SkCamera.h",
   "$_include/utils/SkCanvasStateUtils.h",
-  "$_include/utils/SkCustomTypeface.h",
   "$_include/utils/SkEventTracer.h",
   "$_include/utils/SkInterpolator.h",
   "$_include/utils/SkNWayCanvas.h",
@@ -41,7 +40,6 @@ skia_utils_sources = [
   "$_src/utils/SkCharToGlyphCache.h",
   "$_src/utils/SkClipStackUtils.cpp",
   "$_src/utils/SkClipStackUtils.h",
-  "$_src/utils/SkCustomTypeface.cpp",
   "$_src/utils/SkDashPath.cpp",
   "$_src/utils/SkDashPathPriv.h",
   "$_src/utils/SkEventTracer.cpp",

src/core/SkGlyph.h

@@ -296,7 +296,6 @@ class SkGlyph {
     friend class SkStrikeServer;
     friend class SkTestScalerContext;
     friend class SkTestSVGScalerContext;
-    friend class SkUserScalerContext;
     friend class TestSVGTypeface;
     friend class TestTypeface;
 

src/core/SkTypeface.cpp

@@ -11,7 +11,6 @@
 #include "include/core/SkTypeface.h"
 #include "include/private/SkMutex.h"
 #include "include/private/SkOnce.h"
-#include "include/utils/SkCustomTypeface.h"
 #include "src/core/SkAdvancedTypefaceMetrics.h"
 #include "src/core/SkEndian.h"
 #include "src/core/SkFontDescriptor.h"
@@ -162,12 +161,6 @@ sk_sp<SkTypeface> SkTypeface::MakeFromData(sk_sp<SkData> data, int index) {
 }
 
 sk_sp<SkTypeface> SkTypeface::MakeFromFontData(std::unique_ptr<SkFontData> data) {
-    if (data->hasStream()) {
-        if (auto tf = SkCustomTypefaceBuilder::Deserialize(data->getStream())) {
-            return tf;
-        }
-    }
-
     return SkFontMgr::RefDefault()->makeFromFontData(std::move(data));
 }