Add the ability to select a source image to use in the code.

experimental/webtry/main.cpp

 #include <sys/time.h>
 #include <sys/resource.h>
 
 #include "SkCanvas.h"
 #include "SkCommandLineFlags.h"
 #include "SkData.h"
 #include "SkForceLinking.h"
 #include "SkGraphics.h"
+#include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkImageInfo.h"
 #include "SkStream.h"
 #include "SkSurface.h"
 
 #include "seccomp_bpf.h"
 
 __SK_FORCE_IMAGE_DECODER_LINKING;
 
 DEFINE_string(out, "", "Filename of the PNG to write to.");
+DEFINE_string(source, "", "Filename of the source image.");
+
+// Defined in template.cpp.
+extern SkBitmap source;
 
 static bool install_syscall_filter() {
     struct sock_filter filter[] = {
         /* Grab the system call number. */
         EXAMINE_SYSCALL,
         /* List allowed syscalls. */
         ALLOW_SYSCALL(exit_group),
         ALLOW_SYSCALL(exit),
         ALLOW_SYSCALL(fstat),
         ALLOW_SYSCALL(read),
@@ skipping 53 matching lines @@
 extern void draw(SkCanvas* canvas);
 
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     SkAutoGraphics init;
 
     if (FLAGS_out.count() == 0) {
       perror("The --out flag must have an argument.");
       return 1;
     }
+
+    if (FLAGS_source.count() == 1) {
+       if (!SkImageDecoder::DecodeFile(FLAGS_source[0], &source)) {
+           perror("Unable to read the source image.");
+       }
+    }
+
     SkFILEWStream stream(FLAGS_out[0]);
 
     SkImageInfo info = SkImageInfo::MakeN32(256, 256, kPremul_SkAlphaType);
     SkAutoTUnref<SkSurface> surface(SkSurface::NewRaster(info));
     SkCanvas* canvas = surface->getCanvas();
 
     setLimits();
 
     if (!install_syscall_filter()) {
         return 1;
     }
 
     draw(canvas);
 
     // Write out the image as a PNG.
     SkAutoTUnref<SkImage> image(surface->newImageSnapshot());
     SkAutoTUnref<SkData> data(image->encode(SkImageEncoder::kPNG_Type, 100));
     if (NULL == data.get()) {
         printf("Failed to encode\n");
         exit(1);
     }
     stream.write(data->data(), data->size());
 }