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/Path_068.cpp b/docs/examples/Path_068.cpp
new file mode 100644
index 0000000..3bf95c4
--- /dev/null
+++ b/docs/examples/Path_068.cpp
@@ -0,0 +1,42 @@
+#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=386000684073fccabc224d7d6dc81cd9
+REG_FIDDLE(Path_068, 256, 226, false, 0) {
+void draw(SkCanvas* canvas) {
+    SkPaint tangentPaint;
+    tangentPaint.setAntiAlias(true);
+    SkPaint textPaint(tangentPaint);
+    tangentPaint.setStyle(SkPaint::kStroke_Style);
+    tangentPaint.setColor(SK_ColorGRAY);
+    SkPaint arcPaint(tangentPaint);
+    arcPaint.setStrokeWidth(5);
+    arcPaint.setColor(SK_ColorBLUE);
+    SkPath path;
+    SkPoint pts[] = { {56, 20}, {200, 20}, {90, 190} };
+    SkScalar radius = 50;
+    path.moveTo(pts[0]);
+    path.arcTo(pts[1], pts[2], radius);
+    canvas->drawLine(pts[0], pts[1], tangentPaint);
+    canvas->drawLine(pts[1], pts[2], tangentPaint);
+    SkPoint lastPt;
+    (void) path.getLastPt(&lastPt);
+    SkVector radial = pts[2] - pts[1];
+    radial.setLength(radius);
+    SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX };
+    canvas->drawCircle(center, radius, tangentPaint);
+    canvas->drawLine(lastPt, center, tangentPaint);
+    radial = pts[1] - pts[0];
+    radial.setLength(radius);
+    SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX };
+    canvas->drawLine(center, arcStart, tangentPaint);
+    canvas->drawPath(path, arcPaint);
+    canvas->drawString("(x0, y0)", pts[0].fX - 5, pts[0].fY, textPaint);
+    canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint);
+    canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint);
+    canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint);
+    canvas->drawString("radius", center.fX - 3, center.fY - 16, textPaint);
+}
+}  // END FIDDLE
+#endif  // Disabled until updated to use current API.