Initial QuadTree implementation

gyp/tests.gyp

 # GYP file to build unit tests.
 {
   'includes': [
     'apptype_console.gypi',
   ],
   'targets': [
     {
       'target_name': 'tests',
       'type': 'executable',
       'include_dirs' : [
@@ skipping 14 matching lines @@
       ],
       'includes': [
         'pathops_unittest.gypi',
       ],
       'sources': [
         '../tests/AAClipTest.cpp',
         '../tests/ARGBImageEncoderTest.cpp',
         '../tests/AndroidPaintTest.cpp',
         '../tests/AnnotationTest.cpp',
         '../tests/AtomicTest.cpp',
+        '../tests/BBoxHierarchyTest.cpp',
         '../tests/BitSetTest.cpp',
         '../tests/BitmapCopyTest.cpp',
         '../tests/BitmapGetColorTest.cpp',
         '../tests/BitmapHasherTest.cpp',
         '../tests/BitmapHeapTest.cpp',
         '../tests/BitmapTest.cpp',
         '../tests/BlitRowTest.cpp',
         '../tests/BlurTest.cpp',
         '../tests/CachedDecodingPixelRefTest.cpp',
         '../tests/CanvasStateTest.cpp',
@@ skipping 136 matching lines @@
       'conditions': [
         [ 'skia_gpu == 1', {
           'include_dirs': [
             '../src/gpu',
           ],
         }],
       ],
     },
   ],
 }