Fix the speeling of "purgeable" in Gr code

src/gpu/GrGpuResourceCacheAccess.h

Index: src/gpu/GrGpuResourceCacheAccess.h
diff --git a/src/gpu/GrGpuResourceCacheAccess.h b/src/gpu/GrGpuResourceCacheAccess.h
index 474438fa9ce29407c044feb5df030a40e9a7d8cb..aa2337d7f2528645d0e757652ad7bc953a26c14d 100644
--- a/src/gpu/GrGpuResourceCacheAccess.h
+++ b/src/gpu/GrGpuResourceCacheAccess.h
@@ -86,7 +86,7 @@ public:
      */
     void release() {
         fResource->release();
-        if (fResource->isPurgable()) {            
+        if (fResource->isPurgeable()) {            
             SkDELETE(fResource);
         }
     }
@@ -96,7 +96,7 @@ public:
      */
     void abandon() {
         fResource->abandon();
-        if (fResource->isPurgable()) {            
+        if (fResource->isPurgeable()) {            
             SkDELETE(fResource);
         }
     }