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_032.cpp b/docs/examples/Path_032.cpp
new file mode 100644
index 0000000..4857606
--- /dev/null
+++ b/docs/examples/Path_032.cpp
@@ -0,0 +1,24 @@
+// 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=6b97099acdae80b16df0c4241f593991
+REG_FIDDLE(Path_032, 256, 256, true, 0) {
+void draw(SkCanvas* canvas) {
+    SkPoint points[] = {{1, 0}, {0, 0}, {0, 0}, {0, 0}};
+    SkScalar step = 1;
+    SkScalar prior, length = 0, degenerate = 0;
+    do {
+        prior = points[0].fX;
+        step /= 2;
+        if (SkPath::IsCubicDegenerate(points[0], points[1], points[2], points[3], false)) {
+            degenerate = prior;
+            points[0].fX += step;
+        } else {
+            length = prior;
+            points[0].fX -= step;
+        }
+    } while (prior != points[0].fX);
+    SkDebugf("%1.8g is degenerate\n", degenerate);
+    SkDebugf("%1.8g is length\n", length);
+}
+}  // END FIDDLE