SkRecordDraw: skip draw ops when the clip is empty

tests/RecorderTest.cpp

 #include "Test.h"
 
 #include "SkRecord.h"
 #include "SkRecorder.h"
 #include "SkRecords.h"
 
 #define COUNT(T) + 1
 static const int kRecordTypes = SK_RECORD_TYPES(COUNT);
 #undef COUNT
 
 // Tallies the types of commands it sees into a histogram.
 class Tally {
 public:
     Tally() { sk_bzero(&fHistogram, sizeof(fHistogram)); }
 
     template <typename T>
     void operator()(const T&) { ++fHistogram[T::kType]; }
 
     template <typename T>
     int count() const { return fHistogram[T::kType]; }
 
 private:
     int fHistogram[kRecordTypes];
 };
 
 DEF_TEST(Recorder, r) {
     SkRecord record;
-    SkRecorder recorder(&record, 1920, 1080);
+    SkRecorder recorder(SkRecorder::kWriteOnly_Mode, &record, 1920, 1080);
 
     recorder.drawRect(SkRect::MakeWH(10, 10), SkPaint());
 
     Tally tally;
     record.visit(tally);
 
     REPORTER_ASSERT(r, 1 == tally.count<SkRecords::DrawRect>());
 }