[canvaskit] Add support for woff2 fonts

Requested by Flutter. This adds about 80k of code size
due in large part to the brotli decoding logic.

This also updates the check_deps error to point at
a doc on how to create a new GOB mirror.

Brotli version is 1.0.9; the latest as of today.

Change-Id: I1580cb2189ff1205a9bffca3d887ff2b98a4042e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/333218
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>

DEPS

@@ -8,6 +8,7 @@ deps = {
   "buildtools"                            : "https://chromium.googlesource.com/chromium/buildtools.git@505de88083136eefd056e5ee4ca0f01fe9b33de8",
   "common"                                : "https://skia.googlesource.com/common.git@9737551d7a52c3db3262db5856e6bcd62c462b92",
   "third_party/externals/angle2"          : "https://chromium.googlesource.com/angle/angle.git@72001c7d85ba2be69ccd54768a07e80a7d2756bc",
+  "third_party/externals/brotli"          : "https://skia.googlesource.com/external/github.com/google/brotli.git@e61745a6b7add50d380cfd7d3883dd6c62fc2c71",
   "third_party/externals/d3d12allocator"  : "https://skia.googlesource.com/external/github.com/GPUOpen-LibrariesAndSDKs/D3D12MemoryAllocator.git@169895d529dfce00390a20e69c2f516066fe7a3b",
   # Dawn requires jinja2 and markupsafe for the code generator, and glslang and shaderc for SPIRV compilation.
   # When the Dawn revision is updated these should be updated from the Dawn DEPS as well.

infra/bots/check_deps.py

@@ -50,7 +50,8 @@ def main():
     rev = split[1]
     if not 'googlesource.com' in repo:
       errs.append(
-          'DEPS must be hosted on googlesource.com; %s is not allowed.' % repo)
+          'DEPS must be hosted on googlesource.com; %s is not allowed. '
+          'See http://go/new-skia-git-mirror' % repo)
     if not re.match(r'^[a-z0-9]{40}$', rev):
       errs.append('%s: "%s" does not look like a commit hash.' % (repo, rev))
   if errs:

modules/canvaskit/CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - `getLineMetrics` to Paragraph.
  - `Canvas.saveLayerPaint` as an experimental, undocumented "fast path" if one only needs to pass 
    the paint.
+ - Support for .woff and .woff2 fonts. Disable .woff2 for reduced code size by supplying
+   no_woff2 to compile.sh. (This removes the code to do brotli decompression).
 
 ### Breaking
  - `CanvasKit.MakePathFromSVGString` was renamed to `CanvasKit.Path.MakeFromSVGString`

modules/canvaskit/compile.sh

@@ -174,12 +174,14 @@ if [[ $@ == *no_canvas* ]]; then
 fi
 
 GN_FONT="skia_enable_fontmgr_custom_directory=false "
+WOFF2_FONT="skia_use_freetype_woff2=true"
 FONT_CFLAGS=""
 BUILTIN_FONT=""
 FONT_JS="--pre-js $BASE_DIR/font.js"
 if [[ $@ == *no_font* ]]; then
   echo "Omitting the built-in font(s), font manager and all code dealing with fonts"
   FONT_CFLAGS="-DSK_NO_FONTS"
+  WOFF2_FONT=""
   FONT_JS=""
   GN_FONT+="skia_enable_fontmgr_custom_embedded=false skia_enable_fontmgr_custom_empty=false"
 elif [[ $@ == *no_embedded_font* ]]; then
@@ -196,6 +198,10 @@ else
   GN_FONT+="skia_enable_fontmgr_custom_embedded=true skia_enable_fontmgr_custom_empty=false"
 fi
 
+if [[ $@ == *no_woff2* ]]; then
+  WOFF2_FONT="skia_use_freetype_woff2=false"
+fi
+
 if [[ $@ == *no_alias_font* ]]; then
 EXTRA_CFLAGS+="\"-DCANVASKIT_NO_ALIAS_FONT\","
 FONT_CFLAGS+=" -DCANVASKIT_NO_ALIAS_FONT"
@@ -306,6 +312,7 @@ echo "Compiling bitcode"
   ${GN_SHAPER} \
   ${GN_GPU} \
   ${GN_FONT} \
+  ${WOFF2_FONT} \
   ${GN_PARTICLES} \
   ${GN_VIEWER} \
   \

modules/canvaskit/tests/font.spec.js

@@ -286,12 +286,10 @@ describe('Font Behavior', () => {
             buffer: fetchedByteBuffers[0],
             y: 90,
         },{
-            // Not currently supported by Skia
             type: '.woff font',
             buffer: fetchedByteBuffers[1],
             y: 120,
         },{
-            // Not currently supported by Skia
             type: '.woff2 font',
             buffer: fetchedByteBuffers[2],
             y: 150,

third_party/brotli/BUILD.gn

@@ -0,0 +1,23 @@
+# Copyright 2020 Google LLC
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("../third_party.gni")
+
+third_party("brotli") {
+  public_include_dirs = [ "../externals/brotli/c/include" ]
+
+  # The only consumer of brotli is freetype and it only needs to decode brotli.
+  sources = [
+    "../externals/brotli/c/common/constants.c",
+    "../externals/brotli/c/common/context.c",
+    "../externals/brotli/c/common/dictionary.c",
+    "../externals/brotli/c/common/platform.c",
+    "../externals/brotli/c/common/transform.c",
+    "../externals/brotli/c/dec/bit_reader.c",
+    "../externals/brotli/c/dec/decode.c",
+    "../externals/brotli/c/dec/huffman.c",
+    "../externals/brotli/c/dec/state.c",
+  ]
+}

third_party/freetype2/BUILD.gn

@@ -7,6 +7,7 @@ declare_args() {
   # TODO: build from source all the time for testing?
   skia_use_system_freetype2 =
       (is_official_build || !(is_android || sanitize == "MSAN")) && !is_fuchsia
+  skia_use_freetype_woff2 = false
 }
 
 import("../third_party.gni")
@@ -37,6 +38,11 @@ if (skia_use_system_freetype2) {
       ]
     }
 
+    if (skia_use_freetype_woff2) {
+      deps += [ "//third_party/brotli" ]
+      defines += [ "FT_CONFIG_OPTION_USE_BROTLI" ]
+    }
+
     sources = [
       "../externals/freetype/src/autofit/autofit.c",
       "../externals/freetype/src/base/ftbase.c",