allow SkMutex* as an alternative arg to SkAutoMutexAcquire constructor

git-svn-id: http://skia.googlecode.com/svn/trunk@3754 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 14 insertions, 9 deletions

diff --git a/include/core/SkThread.h b/include/core/SkThread.h
index 1495a16fa9..262ce8ba9a 100644
--- a/include/core/SkThread.h
+++ b/include/core/SkThread.h
@@ -31,24 +31,29 @@ public:
 
 class SkAutoMutexAcquire : SkNoncopyable {
 public:
-    explicit SkAutoMutexAcquire(SkBaseMutex& mutex) : fMutex(&mutex)
-    {
+    explicit SkAutoMutexAcquire(SkBaseMutex& mutex) : fMutex(&mutex) {
         SkASSERT(fMutex != NULL);
         mutex.acquire();
     }
+    
+    SkAutoMutexAcquire(SkBaseMutex* mutex) : fMutex(mutex) {
+        if (mutex) {
+            mutex->acquire();
+        }
+    }
+
     /** If the mutex has not been release, release it now.
     */
-    ~SkAutoMutexAcquire()
-    {
-        if (fMutex)
+    ~SkAutoMutexAcquire() {
+        if (fMutex) {
             fMutex->release();
+        }
     }
+
     /** If the mutex has not been release, release it now.
     */
-    void release()
-    {
-        if (fMutex)
-        {
+    void release() {
+        if (fMutex) {
             fMutex->release();
             fMutex = NULL;
         }