make tests portable by using 565 compatible colors

gm/discard.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 "gm.h"
 #include "SkCanvas.h"
 #include "SkColorShader.h"
@@ skipping 40 matching lines @@
             return;
         }
 
         canvas->clear(SK_ColorBLACK);
 
         SkRandom rand;
         for (int x = 0; x < 10; ++x) {
             for (int y = 0; y < 10; ++y) {
               surface->getCanvas()->discard();
               // Make something that isn't too close to the background color, black.
-              SkColor color = rand.nextU() | 0xFF404040;
+              SkColor color = sk_tool_utils::color_to_565(rand.nextU() | 0xFF404040);
               switch (rand.nextULessThan(3)) {
                   case 0:
                       surface->getCanvas()->drawColor(color);
                       break;
                   case 1:
                       surface->getCanvas()->clear(color);
                       break;
                   case 2:
                       SkColorShader shader(color);
                       SkPaint paint;
@@ skipping 13 matching lines @@
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return SkNEW(DiscardGM); )
 
 } // end namespace
 
 #endif