Force SkPath::getConvexity() cache for thread safety.

src/core/SkRecords.cpp

Index: src/core/SkRecords.cpp
diff --git a/src/core/SkRecords.cpp b/src/core/SkRecords.cpp
index 81dd92f9ef4d103ad9d2b6d0548f75d0ce64b0c6..555f992369a516116a912d1ed60699de1f0752d7 100644
--- a/src/core/SkRecords.cpp
+++ b/src/core/SkRecords.cpp
@@ -11,6 +11,7 @@
 namespace SkRecords {
     PreCachedPath::PreCachedPath(const SkPath& path) : SkPath(path) {
         this->updateBoundsCache();
+        (void)this->getConvexity();
 #if 0  // Disabled to see if we ever really race on this.  It costs time, chromium:496982.
         SkPathPriv::FirstDirection junk;
         (void)SkPathPriv::CheapComputeFirstDirection(*this, &junk);