Remove unnecessary 'const's

Source/platform/graphics/GraphicsContext.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 1865 matching lines @@
             row2[x] = lineColor;
             break;
         case 3:
             row1[x] = antiColor;
             row2[x] = antiColor;
             break;
         }
     }
 }
 
-const SkPMColor GraphicsContext::lineColors(int index)
+SkPMColor GraphicsContext::lineColors(int index)
 {
     static const SkPMColor colors[] = {
         SkPreMultiplyARGB(0xFF, 0xFF, 0x00, 0x00), // Opaque red.
         SkPreMultiplyARGB(0xFF, 0xC0, 0xC0, 0xC0) // Opaque gray.
     };
 
     return colors[index];
 }
 
-const SkPMColor GraphicsContext::antiColors1(int index)
+SkPMColor GraphicsContext::antiColors1(int index)
 {
     static const SkPMColor colors[] = {
         SkPreMultiplyARGB(0xB0, 0xFF, 0x00, 0x00), // Semitransparent red.
         SkPreMultiplyARGB(0xB0, 0xC0, 0xC0, 0xC0)  // Semitransparent gray.
     };
 
     return colors[index];
 }
 
-const SkPMColor GraphicsContext::antiColors2(int index)
+SkPMColor GraphicsContext::antiColors2(int index)
 {
     static const SkPMColor colors[] = {
         SkPreMultiplyARGB(0x60, 0xFF, 0x00, 0x00), // More transparent red
         SkPreMultiplyARGB(0x60, 0xC0, 0xC0, 0xC0)  // More transparent gray
     };
 
     return colors[index];
 }
 #endif
 
@@ skipping 44 matching lines @@
         // FIXME: This is to not break tests (it results in the filter bitmap flag
         // being set to true). We need to decide if we respect InterpolationNone
         // being returned from computeInterpolationQuality.
         resampling = InterpolationLow;
     }
     resampling = limitInterpolationQuality(this, resampling);
     paint->setFilterLevel(static_cast<SkPaint::FilterLevel>(resampling));
 }
 
 } // namespace blink