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/Pixmap_017.cpp b/docs/examples/Pixmap_017.cpp
new file mode 100644
index 0000000..8ebdd5a
--- /dev/null
+++ b/docs/examples/Pixmap_017.cpp
@@ -0,0 +1,36 @@
+// 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=bf31ee140e2c163c3957276e6d4c4f0c
+REG_FIDDLE(Pixmap_017, 256, 256, true, 0) {
+const char* color_type(SkColorType ct) {
+    switch (ct) {
+        case kUnknown_SkColorType:      return "Unknown";
+        case kAlpha_8_SkColorType:      return "Alpha_8";
+        case kRGB_565_SkColorType:      return "RGB_565";
+        case kARGB_4444_SkColorType:    return "ARGB_4444";
+        case kRGBA_8888_SkColorType:    return "RGBA_8888";
+        case kRGB_888x_SkColorType:     return "RGB_888x";
+        case kBGRA_8888_SkColorType:    return "BGRA_8888";
+        case kRGBA_1010102_SkColorType: return "RGBA_1010102";
+        case kRGB_101010x_SkColorType:  return "RGB_101010x";
+        case kGray_8_SkColorType:       return "Gray_8";
+        case kRGBA_F16Norm_SkColorType: return "RGBA_F16Norm";
+        case kRGBA_F16_SkColorType:     return "RGBA_F16";
+        case kRGBA_F32_SkColorType:     return "RGBA_F32";
+        default: SkASSERT(false); return nullptr;
+    }
+}
+void draw(SkCanvas* canvas) {
+    SkImageInfo info = SkImageInfo::MakeA8(1, 1);
+    for (SkColorType colorType : { kUnknown_SkColorType,   kAlpha_8_SkColorType,
+                                   kRGB_565_SkColorType,   kARGB_4444_SkColorType,
+                                   kRGBA_8888_SkColorType, kBGRA_8888_SkColorType,
+                                   kGray_8_SkColorType,    kRGBA_F16_SkColorType } ) {
+        SkPixmap pixmap(info.makeColorType(colorType), nullptr, 4);
+        SkDebugf("color: k" "%s" "_SkColorType" "%*s" "bytesPerPixel: %d shiftPerPixel: %d\n",
+                color_type(colorType), 10 - strlen(color_type(colorType)), " ",
+                pixmap.info().bytesPerPixel(), pixmap.shiftPerPixel());
+    }
+}
+}  // END FIDDLE