Align all SkRecord::alloc() calls up to at least a pointer size.

tests/RecordTest.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 
 #include "SkBitmap.h"
@@ skipping 60 matching lines @@
     Stretch stretch;
     stretch.apply(&record);
 
     // Now its area should be 100 + 400.
     summer.apply(record);
     REPORTER_ASSERT(r, summer.area() == 500);
 }
 
 #undef APPEND
 
+template <typename T>
+static bool is_aligned(const T* p) {
+    return (((uintptr_t)p) & (sizeof(T) - 1)) == 0;
+}
+
+DEF_TEST(Record_Alignment, r) {
+    SkRecord record;
+
+    // Of course a byte's always aligned.
+    REPORTER_ASSERT(r, is_aligned(record.alloc<uint8_t>()));
+
+    // (If packed tightly, the rest below here would be off by one.)
+
+    // It happens that the first implementation always aligned to 4 bytes,
+    // so these two were always correct.
+    REPORTER_ASSERT(r, is_aligned(record.alloc<uint16_t>()));
+    REPORTER_ASSERT(r, is_aligned(record.alloc<uint32_t>()));
+
+    // These two are regression tests (void* only on 64-bit machines).
+    REPORTER_ASSERT(r, is_aligned(record.alloc<uint64_t>()));
+    REPORTER_ASSERT(r, is_aligned(record.alloc<void*>()));
+
+    // We're not testing beyond sizeof(void*), which is where the current implementation will break.
+}
+