Add a class to allocate small objects w/o extra calls to new.

gyp/tests.gypi

Index: gyp/tests.gypi
diff --git a/gyp/tests.gypi b/gyp/tests.gypi
index c2b2c548e33a9a0659e26c6159ce35a3260d02f2..69904642795876d2ca11e9c077154bd2729b9fb9 100644
--- a/gyp/tests.gypi
+++ b/gyp/tests.gypi
@@ -1,3 +1,4 @@
+# Common gypi for unit tests.
 {
   'include_dirs': [
     '../src/core',
@@ -143,6 +144,7 @@
     '../tests/ShaderImageFilterTest.cpp',
     '../tests/ShaderOpacityTest.cpp',
     '../tests/SkBase64Test.cpp',
+    '../tests/SmallAllocatorTest.cpp',
     '../tests/SortTest.cpp',
     '../tests/SrcOverTest.cpp',
     '../tests/StreamTest.cpp',