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/Bitmap_007.cpp b/docs/examples/Bitmap_007.cpp
new file mode 100644
index 0000000..8e55515
--- /dev/null
+++ b/docs/examples/Bitmap_007.cpp
@@ -0,0 +1,26 @@
+// 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=7f972d742dd78d2500034d8867e9ef2f
+REG_FIDDLE(Bitmap_007, 256, 256, true, 0) {
+void draw(SkCanvas* canvas) {
+    SkBitmap bitmap;
+    bitmap.allocPixels(SkImageInfo::MakeN32Premul(10, 11));
+    SkCanvas offscreen(bitmap);
+    offscreen.clear(SK_ColorWHITE);
+    SkPaint paint;
+    SkFont font;
+    font.setEdging(SkFont::Edging::kAlias);
+    offscreen.drawString("&", 0, 10, font, paint);
+    const SkPixmap& pixmap = bitmap.pixmap();
+    if (pixmap.addr()) {
+        SkPMColor pmWhite = *pixmap.addr32(0, 0);
+        for (int y = 0; y < pixmap.height(); ++y) {
+            for (int x = 0; x < pixmap.width(); ++x) {
+                SkDebugf("%c", *pixmap.addr32(x, y) == pmWhite ? '-' : 'x');
+            }
+            SkDebugf("\n");
+        }
+    }
+}
+}  // END FIDDLE