Allow for no pdf rasterizers in gm.

gm/gmmain.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /*
  * Code for the "gm" (Golden Master) rendering comparison tool.
  *
@@ skipping 1312 matching lines @@
 static const PDFRasterizerData kPDFRasterizers[] = {
 #ifdef SK_BUILD_FOR_MAC
     { &SkPDFDocumentToBitmap, "mac",     true },
 #endif
 #ifdef SK_BUILD_POPPLER
     { &SkPopplerRasterizePDF, "poppler", true },
 #endif
 #ifdef SK_BUILD_NATIVE_PDF_RENDERER
     { &SkNativeRasterizePDF,  "native",  true },
 #endif  // SK_BUILD_NATIVE_PDF_RENDERER
+    // The following exists so that this array is never zero length.

[epoger, 2014/05/09 14:35:30]

I take it you investigated making the code properly handle a zero-length array,
but that was more trouble than it was worth?

[bungeman-skia, 2014/05/09 14:56:15]

Well, it's technically against the c++ specification to declare a static/stack
array of length 0. GCC seems to allow it as an extension, but VC++ doesn't allow
it. The only other thing I can think of is to make this an SkTDArray or
something and then init it somewhere. However, that's a lot of extra work.

[epoger, 2014/05/09 15:15:36]

Wow, "The More You Know".  Thanks; I'm a little sheepish that I didn't know this
already!

+    { &SkNoRasterizePDF,      "none",    false},
 };
 
 static const char kDefaultsConfigStr[] = "defaults";
 static const char kExcludeConfigChar = '~';
 
 static SkString configUsage() {
     SkString result;
     result.appendf("Space delimited list of which configs to run. Possible options: [");
     for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
         SkASSERT(gRec[i].fName != kDefaultsConfigStr);
@@ skipping 1112 matching lines @@
     if (FLAGS_forceBWtext) {
         canvas->setDrawFilter(SkNEW(BWTextDrawFilter))->unref();
     }
 }
 
 #if !defined(SK_BUILD_FOR_IOS) && !defined(SK_BUILD_FOR_NACL)
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif