Remove ability for Release code to call getRefCnt() or getWeakRefCnt().

These getRefCnt() methods are not thread safe, so Skia code should not
be calling them.  unique() is fine.

SkDEBUG code (SkASSERTs) can still call getRefCnt() / getWeakRefCnt().

This adds tools/RefCntIs.{h,cpp}, which lets tests make their assertions in
both debug and release modes.

BUG=skia:2726

Committed: https://skia.googlesource.com/skia/+/4ae94ffce5ecf1b71cb5e295b68bf4ec9e697443

R=senorblanco@chromium.org, mtklein@google.com, reed@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/378643003

1 files changed, 8 insertions, 2 deletions

diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 8402a55a22..64603b4cb5 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -361,7 +361,10 @@ static uint32_t compute_hash(const uint32_t* data, int count) {
 
 class CacheImpl : public SkImageFilter::Cache {
 public:
-    explicit CacheImpl(int minChildren) : fMinChildren(minChildren) {}
+    explicit CacheImpl(int minChildren) : fMinChildren(minChildren) {
+        SkASSERT(fMinChildren <= 2);
+    }
+
     virtual ~CacheImpl();
     bool get(const SkImageFilter* key, SkBitmap* result, SkIPoint* offset) SK_OVERRIDE;
     void set(const SkImageFilter* key, const SkBitmap& result, const SkIPoint& offset) SK_OVERRIDE;
@@ -404,7 +407,10 @@ void CacheImpl::remove(const SkImageFilter* key) {
 }
 
 void CacheImpl::set(const SkImageFilter* key, const SkBitmap& result, const SkIPoint& offset) {
-    if (key->getRefCnt() >= fMinChildren) {
+    if (fMinChildren < 2 || !key->unique()) {
+        // We take !key->unique() as a signal that there are probably at least 2 refs on the key,
+        // meaning this filter probably has at least two children and is worth caching when
+        // fMinChildren is 2.  If fMinChildren is less than two, we'll just always cache.
         fData.add(new Value(key, result, offset));
     }
 }