patch from issue 886233004 at patchset 40001 (http://crrev.com/886233004#ps40001)

dm/DMSrcSink.h

 #ifndef DMSrcSink_DEFINED
 #define DMSrcSink_DEFINED
 
 #include "DMGpuSupport.h"
 #include "SkBBHFactory.h"
 #include "SkBBoxHierarchy.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkGPipe.h"
@@ skipping 15 matching lines @@
 struct Src {
     // All Srcs must be thread safe.
     virtual ~Src() {}
     virtual Error SK_WARN_UNUSED_RESULT draw(SkCanvas*) const = 0;
     virtual SkISize size() const = 0;
     virtual Name name() const = 0;
 };
 
 struct Sink {
     virtual ~Sink() {}
-    // You may write to either the bitmap or stream.
-    virtual Error SK_WARN_UNUSED_RESULT draw(const Src&, SkBitmap*, SkWStream*) const
-        = 0;
+    // You may write to either the bitmap or stream.  If you write to log, we'll print that out.
+    virtual Error SK_WARN_UNUSED_RESULT draw(const Src&, SkBitmap*, SkWStream*, SkString* log)
+        const = 0;
     // Sinks in the same enclave (except kAnyThread_Enclave) will run serially on the same thread.
     virtual int enclave() const = 0;
 
     // File extension for the content draw() outputs, e.g. "png", "pdf".
     virtual const char* fileExtension() const  = 0;
 };
 
 enum { kAnyThread_Enclave, kGPU_Enclave, kPDFSink_Enclave };
 static const int kNumEnclaves = kPDFSink_Enclave + 1;
 
@@ skipping 34 matching lines @@
 private:
     Path fPath;
 };
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 class GPUSink : public Sink {
 public:
     GPUSink(GrContextFactory::GLContextType, GrGLStandard, int samples, bool dfText, bool threaded);
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE;
     const char* fileExtension() const SK_OVERRIDE { return "png"; }
 private:
     GrContextFactory::GLContextType fContextType;
     GrGLStandard                    fGpuAPI;
     int                             fSampleCount;
     bool                            fUseDFText;
     bool                            fThreaded;
 };
 
 class PDFSink : public Sink {
 public:
     PDFSink();
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return kPDFSink_Enclave; }
     const char* fileExtension() const SK_OVERRIDE { return "pdf"; }
 };
 
 class RasterSink : public Sink {
 public:
     explicit RasterSink(SkColorType);
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return kAnyThread_Enclave; }
     const char* fileExtension() const SK_OVERRIDE { return "png"; }
 private:
     SkColorType    fColorType;
 };
 
 class SKPSink : public Sink {
 public:
     SKPSink();
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return kAnyThread_Enclave; }
     const char* fileExtension() const SK_OVERRIDE { return "skp"; }
 };
 
 class SVGSink : public Sink {
 public:
     SVGSink();
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return kAnyThread_Enclave; }
     const char* fileExtension() const SK_OVERRIDE { return "svg"; }
 };
 
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 class ViaMatrix : public Sink {
 public:
     ViaMatrix(SkMatrix, Sink*);
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return fSink->enclave(); }
     const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
 private:
     SkMatrix            fMatrix;
     SkAutoTDelete<Sink> fSink;
 };
 
 class ViaPipe : public Sink {
 public:
     explicit ViaPipe(Sink*);
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return fSink->enclave(); }
     const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
 private:
     SkAutoTDelete<Sink>  fSink;
 };
 
 class ViaSerialization : public Sink {
 public:
     explicit ViaSerialization(Sink*);
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return fSink->enclave(); }
     const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
 private:
     SkAutoTDelete<Sink> fSink;
 };
 
 class ViaTiles : public Sink {
 public:
     ViaTiles(int w, int h, SkBBHFactory*, Sink*);
 
-    Error draw(const Src&, SkBitmap*, SkWStream*) const SK_OVERRIDE;
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return fSink->enclave(); }
     const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
 private:
     const int                   fW, fH;
     SkAutoTDelete<SkBBHFactory> fFactory;
     SkAutoTDelete<Sink>         fSink;
 };
 
 class NullSink : public Sink {
 public:
-    Error draw(const Src& src, SkBitmap*, SkWStream* out) const SK_OVERRIDE {
+    Error draw(const Src& src, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE {
         return src.draw(SkCreateNullCanvas());
     }
     int enclave() const SK_OVERRIDE { return kAnyThread_Enclave; }
     const char* fileExtension() const SK_OVERRIDE { return ""; }
 };
 
 }  // namespace DM
 
 #endif//DMSrcSink_DEFINED