Add config options to run different GPU APIs to dm and nanobench

tools/flags/SkCommonFlagsConfig.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SK_COMMON_FLAGS_CONFIG_H
+#define SK_COMMON_FLAGS_CONFIG_H
+
+#include "SkCommandLineFlags.h"
+
+#if SK_SUPPORT_GPU
+#include "GrContextFactory.h"
+#endif
+
+DECLARE_string(config);
+
+#if SK_SUPPORT_GPU
+class SkCommandLineConfigGpu;
+#endif
+
+// SkCommandLineConfig represents a Skia rendering configuration string.
+// The string has following form:
+//   [via-]*tag
+// where 'tag' consists of chars excluding hyphen or "angle-gl"

[mtklein, 2015/12/16 13:31:11]

Have you considered calling this angle_gl so that it doesn't need to be an
exception?

+// and each 'via' consists of chars excluding hyphen.
+class SkCommandLineConfig {
+  public:
+    SkCommandLineConfig(const SkString& tag, const SkTArray<SkString>& viaParts);
+    virtual ~SkCommandLineConfig();
+#if SK_SUPPORT_GPU
+    virtual const SkCommandLineConfigGpu* asConfigGpu() const { return nullptr; }
+#endif
+    const SkString& getTag() const { return fTag; }
+    const SkTArray<SkString>& getViaParts() const { return fViaParts; }
+  private:
+    SkString fTag;
+    SkTArray<SkString> fViaParts;
+};
+
+#if SK_SUPPORT_GPU
+// SkCommandLineConfigGpu is a SkCommandLineConfig that extracts information out of the tag.  It is
+// constructed configs that have:
+// * tags of form "gpu(option=value,option2=value,...)"
+// * tags that represent a shorthand of above (such as "msaa16" representing "gpu(samples=16)")
+class SkCommandLineConfigGpu : public SkCommandLineConfig {
+  public:
+    typedef GrContextFactory::GLContextType ContextType;
+    SkCommandLineConfigGpu(const SkString& tag, const SkTArray<SkString>& viaParts,
+                           ContextType contextType, bool useNVPR, bool useDIText, int samples);
+    const SkCommandLineConfigGpu* asConfigGpu() const override { return this; }
+    ContextType getContextType() const { return fContextType; }
+    bool getUseNVPR() const { return fUseNVPR; }
+    bool getUseDIText() const { return fUseDIText; }
+    int getSamples() const { return fSamples; }
+
+  private:
+    ContextType fContextType;
+    bool fUseNVPR;
+    bool fUseDIText;
+    int fSamples;
+};
+#endif
+
+typedef SkTArray<SkAutoTDelete<SkCommandLineConfig>, true> SkCommandLineConfigArray;
+void ParseConfigs(const SkCommandLineFlags::StringArray& configList,
+                  SkCommandLineConfigArray* outResult);
+
+#endif