ccpr: Don't use the GrContext id for the path cache id

Currently this is probably safe, but somebody could easily make a
change in the future that adds another path cache to the context and
accidentally introduces tricky bugs.

TBR=brianosman@google.com

Bug: chromium:897510
Bug: chromium:897413
Bug: chromium:897245
Bug: chromium:897507
Change-Id: I6bc40ac671058f78eb290dd775612d99008d32e7
Reviewed-on: https://skia-review.googlesource.com/c/164700
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
diff --git a/src/gpu/ccpr/GrCCPathCache.h b/src/gpu/ccpr/GrCCPathCache.h
index e8ce928..54a835a 100644
--- a/src/gpu/ccpr/GrCCPathCache.h
+++ b/src/gpu/ccpr/GrCCPathCache.h
@@ -24,7 +24,7 @@
  */
 class GrCCPathCache {
 public:
-    GrCCPathCache(uint32_t contextUniqueID) : fInvalidatedEntriesInbox(contextUniqueID) {}
+    GrCCPathCache();
     SkDEBUGCODE(~GrCCPathCache();)
 
     // Stores the components of a transformation that affect a path mask (i.e. everything but