Avoid the use of mipmaps to prevent memory leak

src/core/SkBitmapProcState.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapCache.h"
 #include "SkBitmapProcState.h"
 #include "SkColorPriv.h"
@@ skipping 234 matching lines @@
             return false;
         }
 
         // else set the filter-level to Medium, since we're scaling down and
         // want to reqeust mipmaps
         fFilterLevel = SkPaint::kMedium_FilterLevel;
     }
 
     SkASSERT(SkPaint::kMedium_FilterLevel == fFilterLevel);
 
-    /**
-     *  Medium quality means use a mipmap for down-scaling, and just bilper
-     *  for upscaling. Since we're examining the inverse matrix, we look for
-     *  a scale > 1 to indicate down scaling by the CTM.
-     */
-    if (scaleSqd > SK_Scalar1) {
-        fCurrMip.reset(SkMipMapCache::FindAndRef(fOrigBitmap));
-        if (NULL == fCurrMip.get()) {
-            fCurrMip.reset(SkMipMap::Build(fOrigBitmap));
-            if (NULL == fCurrMip.get()) {
-                return false;
-            }
-            SkMipMapCache::Add(fOrigBitmap, fCurrMip);
-        }
-
-        SkScalar levelScale = SkScalarInvert(SkScalarSqrt(scaleSqd));
-        SkMipMap::Level level;
-        if (fCurrMip->extractLevel(levelScale, &level)) {
-            SkScalar invScaleFixup = level.fScale;
-            fInvMatrix.postScale(invScaleFixup, invScaleFixup);
-
-            const SkImageInfo info = fOrigBitmap.info().makeWH(level.fWidth, level.fHeight);
-            // todo: if we could wrap the fCurrMip in a pixelref, then we could just install
-            //       that here, and not need to explicitly track it ourselves.
-            fScaledBitmap.installPixels(info, level.fPixels, level.fRowBytes);
-            fBitmap = &fScaledBitmap;
-            fFilterLevel = SkPaint::kLow_FilterLevel;
-            return true;
-        }
-    }
+    // HACK: Disable use of mipmaps in M39 since they do not use discardable
+    // memory in the cache.
+    fFilterLevel = SkPaint::kLow_FilterLevel;
 
     return false;
 }
 
 static bool get_locked_pixels(const SkBitmap& src, int pow2, SkBitmap* dst) {
     SkPixelRef* pr = src.pixelRef();
     if (pr && pr->decodeInto(pow2, dst)) {
         return true;
     }
 
@@ skipping 711 matching lines @@
     } else {
         size >>= 2;
     }
 
     if (fFilterLevel != SkPaint::kNone_FilterLevel) {
         size >>= 1;
     }
 
     return size;
 }