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/Canvas_120.cpp b/docs/examples/Canvas_120.cpp
new file mode 100644
index 0000000..9676064
--- /dev/null
+++ b/docs/examples/Canvas_120.cpp
@@ -0,0 +1,32 @@
+#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=4e8b7409531c9211a2afcf632005a38c
+REG_FIDDLE(Canvas_120, 256, 256, false, 0) {
+void draw(SkCanvas* canvas) {
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    SkPoint cubics[] = { { 3, 1 },    { 4, 2 }, { 5, 1 },    { 7, 3 },
+                      /* { 7, 3 }, */ { 6, 4 }, { 7, 5 },    { 5, 7 },
+                      /* { 5, 7 }, */ { 4, 6 }, { 3, 7 },    { 1, 5 },
+                      /* { 1, 5 }, */ { 2, 4 }, { 1, 3 }, /* { 3, 1 } */ };
+    SkColor colors[] = { SK_ColorRED, SK_ColorBLUE, SK_ColorYELLOW, SK_ColorCYAN };
+    canvas->scale(30, 30);
+    canvas->drawPatch(cubics, colors, nullptr, paint);
+    SkPoint text[] = { {3,0.9f}, {4,2.5f}, {5,0.9f}, {7.5f,3.2f}, {5.5f,4.2f},
+            {7.5f,5.2f}, {5,7.5f}, {4,5.9f}, {3,7.5f}, {0.5f,5.2f}, {2.5f,4.2f},
+            {0.5f,3.2f} };
+    paint.setTextSize(18.f / 30);
+    for (int i = 0; i< 10; ++i) {
+       char digit = '0' + i;
+       canvas->drawText(&digit, 1, text[i].fX, text[i].fY, paint);
+    }
+    canvas->drawString("10", text[10].fX, text[10].fY, paint);
+    canvas->drawString("11", text[11].fX, text[11].fY, paint);
+    paint.setStyle(SkPaint::kStroke_Style);
+    canvas->drawPoints(SkCanvas::kPolygon_PointMode, 12, cubics, paint);
+    canvas->drawLine(cubics[11].fX, cubics[11].fY, cubics[0].fX, cubics[0].fY, paint);
+}
+}  // END FIDDLE
+#endif  // Disabled until updated to use current API.