skia: Add ANGLE support on Mac

src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp

Index: src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp
diff --git a/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp b/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp
index 1ebd376288be575b9b633c2af3b47f9f2bae8da6..834e122f574944f2ef3a699529c70c80210682af 100644
--- a/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp
+++ b/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp
@@ -27,6 +27,8 @@ const GrGLInterface* GrGLCreateANGLEInterface() {
         // We load the ANGLE library and never let it go
 #if defined _WIN32
         gANGLELib = DynamicLoadLibrary("libGLESv2.dll");
+#elif defined SK_BUILD_FOR_MAC
+        gANGLELib = DynamicLoadLibrary("libGLESv2.dylib");
 #else
         gANGLELib = DynamicLoadLibrary("libGLESv2.so");
 #endif // defined _WIN32