[WIP] Add Context to SkDrawLooper.

src/core/SkSmallAllocator.h

 /*
  * Copyright 2014 Google, Inc
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkSmallAllocator_DEFINED
 #define SkSmallAllocator_DEFINED
 
@@ skipping 78 matching lines @@
     template<typename T, typename A1, typename A2, typename A3>
     T* createT(const A1& a1, const A2& a2, const A3& a3) {
         void* buf = this->reserveT<T>();
         if (NULL == buf) {
             return NULL;
         }
         SkNEW_PLACEMENT_ARGS(buf, T, (a1, a2, a3));
         return static_cast<T*>(buf);
     }
 
-private:
     /*
-     *  Helper function to provide space for one T. The space will be in
-     *  fStorage if there is room, or on the heap otherwise. Either way, this
-     *  class will call ~T() in its destructor and free the heap allocation if
-     *  necessary.
+     *  Reserve a specified amount of space (must be enough space for one T).
+     *  The space will be in fStorage if there is room, or on the heap otherwise.
+     *  Either way, this class will call ~T() in its destructor and free the heap
+     *  allocation if necessary.
+     *  Unlike createT(), this method will not call the constructor of T.
      */
-    template<typename T> void* reserveT() {
+    template<typename T> void* reserveT(size_t storageRequired = sizeof(T)) {
         SkASSERT(fNumObjects < kMaxObjects);
+        SkASSERT(storageRequired >= sizeof(T));
         if (kMaxObjects == fNumObjects) {
             return NULL;
         }
         const size_t storageRemaining = SkAlign4(kTotalBytes) - fStorageUsed;
-        const size_t storageRequired = SkAlign4(sizeof(T));
+        storageRequired = SkAlign4(storageRequired);
         Rec* rec = &fRecs[fNumObjects];
         if (storageRequired > storageRemaining) {
             // Allocate on the heap. Ideally we want to avoid this situation,
             // but we're not sure we can catch all callers, so handle it but
             // assert false in debug mode.
             SkASSERT(false);
             rec->fHeapStorage = sk_malloc_throw(storageRequired);
             rec->fObj = static_cast<void*>(rec->fHeapStorage);
         } else {
             // There is space in fStorage.
@@ skipping 16 matching lines @@
 
     // Number of bytes used so far.
     size_t              fStorageUsed;
     // Pad the storage size to be 4-byte aligned.
     uint32_t            fStorage[SkAlign4(kTotalBytes) >> 2];
     uint32_t            fNumObjects;
     Rec                 fRecs[kMaxObjects];
 };
 
 #endif // SkSmallAllocator_DEFINED