[debugger] Fix build after update to emsdk 2.0.20

Debugger had been including some egl code, which started throwing
an error about eglGetProcAddress not being linked in.

Change-Id: I2e930dc5064b6fc238d3399fe8aba5fe105a3097
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/412986
Reviewed-by: Kevin Lubick <kjlubick@google.com>

experimental/wasm-skp-debugger/compile.sh

@@ -25,7 +25,7 @@ EMAR=`which emar`
 if [[ $@ == *debug* ]]; then
   echo "Building a Debug build"
   EXTRA_CFLAGS="\"-DSK_DEBUG\","
-  RELEASE_CONF="-O0 --js-opts 0 -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=1 -s GL_ASSERTIONS=1 -g4 \
+  RELEASE_CONF="-O0 --js-opts 0 -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=1 -s GL_ASSERTIONS=1 -g3 \
                 --source-map-base /node_modules/debugger/bin/ -DSK_DEBUG"
   BUILD_DIR=${BUILD_DIR:="out/debugger_wasm_debug"}
 else
@@ -48,7 +48,6 @@ python tools/embed_resources.py \
     --output $BASE_DIR/fonts/NotoMono-Regular.ttf.cpp \
     --align 4
 
-GN_GPU="skia_enable_gpu=true skia_gl_standard = \"webgl\""
 GN_GPU_FLAGS="\"-DSK_DISABLE_LEGACY_SHADERCONTEXT\","
 WASM_GPU="-lEGL -lGL -lGLESv2 -DSK_SUPPORT_GPU=1 -DSK_GL \
           -DSK_DISABLE_LEGACY_SHADERCONTEXT --pre-js $BASE_DIR/cpu.js --pre-js $BASE_DIR/gpu.js"
@@ -86,7 +85,6 @@ echo "Compiling bitcode"
   \
   skia_use_angle=false \
   skia_use_dng_sdk=false \
-  skia_use_egl=true \
   skia_use_expat=false \
   skia_use_fontconfig=false \
   skia_use_freetype=true \
@@ -107,7 +105,8 @@ echo "Compiling bitcode"
   skia_use_system_zlib=false\
   skia_use_vulkan=false \
   skia_use_zlib=true \
-  ${GN_GPU} \
+  skia_enable_gpu=true \
+  skia_gl_standard=\"webgl\" \
   skia_enable_tools=false \
   skia_enable_skshaper=false \
   skia_enable_ccpr=false \