[skia] Build fix for upstream build changes. (#3967)

* [skia] Update diff for upstream change.

SkReadBuffer::getArrayCount() implementation changed, so update the
diff.

* [skia] Build fix for upstream build changes.

Skia is changing its build a little bit. 'skia_enable_fontmgr_custom'
has become 'skia_enable_fontmgr_custom_directory' (since that is what
it actually did) and skia_enable_fontmgr_custom_embedded has been added.

* [skia] Update SwiftShader to something not so old.

Skia builds it without submodules. Only build libGLESv2 and libEGL
instead of building everything, which isn't needed and takes a long
time. SwiftShader already has a checked-in build/ directory, so use a
different directory for building. Limit the number of make jobs to avoid
'Cannot allocate memory' errors. To build SwiftShader with a sanitizer,
the cmake define is now like SWIFTSHADER_XSAN.

projects/skia/Dockerfile

@@ -34,8 +34,7 @@ RUN bin/sync
 WORKDIR $SRC/skia/third_party/externals/swiftshader/
 # TODO(metzman): Come up with a better long term solution, such as downloading
 # prebuilt libraries, than pinning swiftshader to a known working revision.
-RUN git checkout bf8fd5b5fb6892dabcc21b4b86d41cd40cb9b4b5
-RUN git submodule update --init
+RUN git checkout 45510ad8a77862c1ce2e33f0efed41544f5f048b
 WORKDIR $SRC/skia
 
 RUN wget -O $SRC/skia/image_filter_deserialize_seed_corpus.zip https://storage.googleapis.com/skia-fuzzer/oss-fuzz/image_filter_deserialize_seed_corpus.zip

projects/skia/build.sh

@@ -18,26 +18,27 @@
 # Build SwiftShader
 pushd third_party/externals/swiftshader/
 export SWIFTSHADER_INCLUDE_PATH=$PWD/include
-rm -rf build
-mkdir build
+# SwiftShader already has a build/ directory, use something else
+rm -rf build_swiftshader
+mkdir build_swiftshader
 
-cd build
+cd build_swiftshader
 if [ $SANITIZER == "coverage" ]; then
   cmake ..
 else
   if [ $SANITIZER == "address" ]; then
-    CMAKE_SANITIZER="ASAN"
+    CMAKE_SANITIZER="SWIFTSHADER_ASAN"
   elif [ $SANITIZER == "memory" ]; then
-    CMAKE_SANITIZER="MSAN"
+    CMAKE_SANITIZER="SWIFTSHADER_MSAN"
   elif [ $SANITIZER == "undefined" ]; then
-    CMAKE_SANITIZER="UBSAN"
+    CMAKE_SANITIZER="SWIFTSHADER_UBSAN"
   else
     exit 1
   fi
   CFLAGS= CXXFLAGS="-stdlib=libc++" cmake .. -D$CMAKE_SANITIZER=1
 fi
 
-make -j
+make -j2 libGLESv2 libEGL
 cp libGLESv2.so libEGL.so $OUT
 export SWIFTSHADER_LIB_PATH=$OUT
 
@@ -67,7 +68,8 @@ $SRC/depot_tools/gn gen out/Fuzz\
       extra_cflags_c=["'"$CFLAGS_ARR"'"]
       extra_cflags_cc=["'"$CXXFLAGS_ARR"'"]
       extra_ldflags=["'"$LDFLAGS_ARR"'"]
-      skia_enable_fontmgr_custom=false
+      skia_enable_fontmgr_custom_directory=false
+      skia_enable_fontmgr_custom_embedded=false
       skia_enable_fontmgr_custom_empty=true
       skia_enable_gpu=true
       skia_enable_skottie=true
@@ -84,7 +86,8 @@ $SRC/depot_tools/gn gen out/Fuzz_mem_constraints\
       extra_cflags_c=["'"$CFLAGS_ARR"'"]
       extra_cflags_cc=["'"$CXXFLAGS_ARR"'","-DIS_FUZZING"]
       extra_ldflags=["'"$LDFLAGS_ARR"'"]
-      skia_enable_fontmgr_custom=false
+      skia_enable_fontmgr_custom_directory=false
+      skia_enable_fontmgr_custom_embedded=false
       skia_enable_fontmgr_custom_empty=true
       skia_enable_gpu=true
       skia_enable_skottie=true

projects/skia/skia.diff

@@ -134,15 +134,17 @@ diff --git a/src/core/SkReadBuffer.cpp b/src/core/SkReadBuffer.cpp
 index c7e26df8d4..eb9b28141d 100644
 --- a/src/core/SkReadBuffer.cpp
 +++ b/src/core/SkReadBuffer.cpp
-@@ -277,7 +277,12 @@ sk_sp<SkData> SkReadBuffer::readByteArrayAsData() {
+@@ -299,8 +299,13 @@ sk_sp<SkData> SkReadBuffer::readByteArrayAsData() {
  uint32_t SkReadBuffer::getArrayCount() {
      const size_t inc = sizeof(uint32_t);
-     fError = fError || !IsPtrAlign4(fReader.peek()) || !fReader.isAvailable(inc);
+     if (!this->validate(IsPtrAlign4(fCurr) && this->isAvailable(inc))) {
+         return 0;
+     }
 +#if defined(IS_FUZZING)
-+    uint32_t retVal = fError ? 0 : *(uint32_t*)fReader.peek();
++    uint32_t retVal = *(uint32_t*)fCurr;
 +    return retVal < 1000 ? retVal: 1000;
 +#else
-     return fError ? 0 : *(uint32_t*)fReader.peek();
+     return *((uint32_t*)fCurr);
 +#endif
  }