Compile all fiddle examples locally

Motivation: it would be a good idea if the API documentation examples
were checked into the skia repository, so we could make sure they
compile as part of the commit queue.

Fiddle would make/update a named fiddle each time it gets a new
commit of Skia, extracted from the code in the examples/ directory.
The docs would point at those named fiddles.  Named fiddles have urls
in the form:

    https://fiddle.skia.org/c/@Bitmap_000

Then we would stick a link to the example into the header documentation
like this:

    /** Allocates the pixel memory for the bitmap, given its dimensions
        and SkColorType. Returns true on success, where success means
        either setPixels() or setPixelRef() was called.

        @param bitmap  SkBitmap containing SkImageInfo as input, and
                       SkPixelRef as output
        @return        true if SkPixelRef was allocated

        @example       https://fiddle.skia.org/c/@Bitmap_000
    */
    bool allocPixelRef(SkBitmap* bitmap) override;

There are still around 200 disabled examples that need to be fixed
(these result from API changes since the author left).

Change-Id: I14a31348a9ccaaa31f65424b91e3a3533d2583a7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/198824
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
diff --git a/docs/examples/Surface_021.cpp b/docs/examples/Surface_021.cpp
new file mode 100644
index 0000000..ed58a38
--- /dev/null
+++ b/docs/examples/Surface_021.cpp
@@ -0,0 +1,25 @@
+#if 0  // Disabled until updated to use current API.
+// Copyright 2019 Google LLC.
+// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
+#include "fiddle/examples.h"
+// HASH=9f454fb93bca6482598d198b4121f0a6
+REG_FIDDLE(Surface_021, 256, 32, false, 0) {
+void draw(SkCanvas* canvas) {
+    sk_sp<SkSurface> surf(SkSurface::MakeRasterN32Premul(64, 64));
+    auto surfCanvas = surf->getCanvas();
+    surfCanvas->clear(SK_ColorRED);
+    SkPaint paint;
+    paint.setTextSize(40);
+    surfCanvas->drawString("&", 0, 32, paint);
+    std::vector<SkPMColor> storage;
+    storage.resize(surf->width() * surf->height());
+    SkPixmap pixmap(SkImageInfo::MakeN32Premul(32, 32), &storage.front(),
+                    surf->width() * sizeof(storage[0]));
+    if (surf->readPixels(pixmap, 0, 0)) {
+        SkBitmap surfBits;
+        surfBits.installPixels(pixmap);
+        canvas->drawBitmap(surfBits, 0, 0);
+    }
+}
+}  // END FIDDLE
+#endif  // Disabled until updated to use current API.