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

tests/RecordTest.cpp

Index: tests/RecordTest.cpp
diff --git a/tests/RecordTest.cpp b/tests/RecordTest.cpp
index 2240ae985825ee270525ba51a0299d56f52fdd0f..2a0e615516d01df8391a6fee2a7f32f8d56cbf95 100644
--- a/tests/RecordTest.cpp
+++ b/tests/RecordTest.cpp
@@ -78,3 +78,28 @@ DEF_TEST(Record, r) {
 
 #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.
+}
+