DM: add --pipe

dm/DMPipeTask.h

Index: dm/DMPipeTask.h
diff --git a/dm/DMPipeTask.h b/dm/DMPipeTask.h
new file mode 100644
index 0000000000000000000000000000000000000000..23bbfef1148a12c2b4f328831d95f37fa4ae169a
--- /dev/null
+++ b/dm/DMPipeTask.h
@@ -0,0 +1,37 @@
+#ifndef DMPipeTask_DEFINED
+#define DMPipeTask_DEFINED
+
+#include "DMTask.h"
+#include "SkBitmap.h"
+#include "SkString.h"
+#include "SkTemplates.h"
+#include "gm.h"
+
+// Sends a GM through a pipe, draws it, and compares against the reference bitmap.
+
+namespace DM {
+
+class PipeTask : public Task {
+
+public:
+    PipeTask(const Task& parent,        // PipeTask must be a child task.  Pass its parent here.
+             skiagm::GM*,               // GM to run through a pipe.  Takes ownership.
+             SkBitmap reference,        // Bitmap to compare pipe results to.
+             bool crossProcess,         // Should we set up a cross process pipe?
+             bool sharedAddressSpace);  // If cross process, should it assume shared address space?
+
+    virtual void draw() SK_OVERRIDE;
+    virtual bool usesGpu() const SK_OVERRIDE { return false; }
+    virtual bool shouldSkip() const SK_OVERRIDE;
+    virtual SkString name() const SK_OVERRIDE { return fName; }
+
+private:
+    const uint32_t fFlags;
+    const SkString fName;
+    SkAutoTDelete<skiagm::GM> fGM;
+    const SkBitmap fReference;
+};
+
+}  // namespace DM
+
+#endif  // DMPipeTask_DEFINED