[canvaskit] Upgrade emscripten to .27

This should have some slightly better, more minified JS and other
bugfixes

Bug: skia:
Change-Id: I7c5367b6650267ec8bafcc5de9e351bd8788392b
Reviewed-on: https://skia-review.googlesource.com/c/193582
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>

experimental/canvaskit/gpu.js

@@ -13,19 +13,19 @@
       function makeWebGLContext(canvas, attrs) {
         // These defaults come from the emscripten _emscripten_webgl_create_context
         var contextAttributes = {
-          'alpha': get(attrs, 'alpha', 1),
-          'depth': get(attrs, 'depth', 1),
-          'stencil': get(attrs, 'stencil', 0),
-          'antialias': get(attrs, 'antialias', 1),
-          'premultipliedAlpha': get(attrs, 'premultipliedAlpha', 1),
-          'preserveDrawingBuffer': get(attrs, 'preserveDrawingBuffer', 0),
-          'preferLowPowerToHighPerformance': get(attrs, 'preferLowPowerToHighPerformance', 0),
-          'failIfMajorPerformanceCaveat': get(attrs, 'failIfMajorPerformanceCaveat', 0),
-          'majorVersion': get(attrs, 'majorVersion', 1),
-          'minorVersion': get(attrs, 'minorVersion', 0),
-          'enableExtensionsByDefault': get(attrs, 'enableExtensionsByDefault', 1),
-          'explicitSwapControl': get(attrs, 'explicitSwapControl', 0),
-          'renderViaOffscreenBackBuffer': get(attrs, 'renderViaOffscreenBackBuffer', 0),
+          alpha: get(attrs, 'alpha', 1),
+          depth: get(attrs, 'depth', 1),
+          stencil: get(attrs, 'stencil', 0),
+          antialias: get(attrs, 'antialias', 1),
+          premultipliedAlpha: get(attrs, 'premultipliedAlpha', 1),
+          preserveDrawingBuffer: get(attrs, 'preserveDrawingBuffer', 0),
+          preferLowPowerToHighPerformance: get(attrs, 'preferLowPowerToHighPerformance', 0),
+          failIfMajorPerformanceCaveat: get(attrs, 'failIfMajorPerformanceCaveat', 0),
+          majorVersion: get(attrs, 'majorVersion', 1),
+          minorVersion: get(attrs, 'minorVersion', 0),
+          enableExtensionsByDefault: get(attrs, 'enableExtensionsByDefault', 1),
+          explicitSwapControl: get(attrs, 'explicitSwapControl', 0),
+          renderViaOffscreenBackBuffer: get(attrs, 'renderViaOffscreenBackBuffer', 0),
         };
         if (!canvas) {
           SkDebug('null canvas passed into makeWebGLContext');
@@ -36,6 +36,8 @@
           SkDebug('explicitSwapControl is not supported');
           return 0;
         }
+        // GL is an enscripten provided helper
+        // See https://github.com/emscripten-core/emscripten/blob/incoming/src/library_webgl.js
         return GL.createContext(canvas, contextAttributes);
       }
 

infra/pathkit/docker/Makefile

@@ -1,4 +1,4 @@
-EMSDK_VERSION=1.38.16_v1
+EMSDK_VERSION=1.38.27_v1
 
 # Can check CHROME_VERSION with
 # docker run karma-chrome-tests /usr/bin/google-chrome-stable --version

infra/pathkit/docker/emsdk-base/Dockerfile

@@ -1,7 +1,7 @@
 # A Docker image that has the Emscripten SDK installed to /opt/emsdk
 # Use this image to compile C/C++ code to WASM.
 
-FROM launcher.gcr.io/google/clang-debian9 AS build
+FROM launcher.gcr.io/google/clang-debian9
 RUN apt-get update && apt-get upgrade -y && apt-get install -y \
   git \
   python \
@@ -16,9 +16,9 @@ WORKDIR /opt/emsdk
 RUN ./emsdk update-tags
 
 # These versions were available and worked on my local desktop as of Nov 6 2018.
-RUN ./emsdk install emscripten-1.38.16 node-8.9.1-64bit clang-e1.38.16-64bit
+RUN ./emsdk install sdk-1.38.27-64bit
 
-RUN ./emsdk activate emscripten-1.38.16 node-8.9.1-64bit clang-e1.38.16-64bit
+RUN ./emsdk activate sdk-1.38.27-64bit
 
 RUN /bin/bash -c "source ./emsdk_env.sh"
 

modules/pathkit/pathkit_wasm_bindings.cpp

@@ -226,7 +226,7 @@ JSString EMSCRIPTEN_KEEPALIVE ToSVGString(const SkPath& path) {
     // Wrapping it in val automatically turns it into a JS string.
     // Not too sure on performance implications, but is is simpler than
     // returning a raw pointer to const char * and then using
-    // Pointer_stringify() on the calling side.
+    // UTF8ToString() on the calling side.
     return emscripten::val(s.c_str());
 }