add pathops debugging

src/pathops/SkPathOpsDebug.h

Index: src/pathops/SkPathOpsDebug.h
diff --git a/src/pathops/SkPathOpsDebug.h b/src/pathops/SkPathOpsDebug.h
index e7849ffbaf8b3c4e1bdf3e2b5668fbb15d7b1653..c1b1adb7072a750cf3e883cec1f8d3d9f2bf8171 100644
--- a/src/pathops/SkPathOpsDebug.h
+++ b/src/pathops/SkPathOpsDebug.h
@@ -49,6 +49,7 @@
 #define DEBUG_ANGLE 0
 #define DEBUG_ASSEMBLE 0
 #define DEBUG_COINCIDENCE 0
+#define DEBUG_COINCIDENCE_ORDER 0
 #define DEBUG_COINCIDENCE_VERBOSE 0
 #define DEBUG_CUBIC_BINARY_SEARCH 0
 #define DEBUG_CUBIC_SPLIT 0
@@ -67,7 +68,6 @@
 #define DEBUG_WINDING 0
 #define DEBUG_WINDING_AT_T 0
 
-
 #else
 
 #define DEBUG_ACTIVE_OP 1
@@ -78,6 +78,7 @@
 #define DEBUG_ANGLE 1
 #define DEBUG_ASSEMBLE 1
 #define DEBUG_COINCIDENCE 01
+#define DEBUG_COINCIDENCE_ORDER 0
 #define DEBUG_COINCIDENCE_VERBOSE 01
 #define DEBUG_CUBIC_BINARY_SEARCH 0
 #define DEBUG_CUBIC_SPLIT 1
@@ -155,6 +156,13 @@
 #include "SkTLS.h"
 #endif
 
+#define FAIL_IF(cond) do { bool fail = (cond); SkOPASSERT(!fail); if (fail) return false; } \
+        while (false)
+
+#define RETURN_FALSE_IF(abort, cond) \
+        do { bool fail = (cond); SkOPASSERT(!(abort) || !fail); if (fail) return false; } \
+        while (false)
+
 class SkPathOpsDebug {
 public:
     static const char* kLVerbStr[];