Bug 746344 - gfxImageSurface should allow allocation without memset. r=jmuizelaar a=jpr

--HG--
extra : rebase_source : 271a72ec7911299d2a185df7c5139c00997e55df

gfx/thebes/gfxImageSurface.cpp

@@ -123,7 +123,7 @@ TryAllocAlignedBytes(size_t aSize)
 #endif
 }
 
-gfxImageSurface::gfxImageSurface(const gfxIntSize& size, gfxImageFormat format) :
+gfxImageSurface::gfxImageSurface(const gfxIntSize& size, gfxImageFormat format, bool aClear) :
     mSize(size), mOwnsData(false), mData(nsnull), mFormat(format)
 {
     mStride = ComputeStride();
@@ -139,7 +139,8 @@ gfxImageSurface::gfxImageSurface(const gfxIntSize& size, gfxImageFormat format)
         mData = (unsigned char *) TryAllocAlignedBytes(mSize.height * mStride);
         if (!mData)
             return;
-        memset(mData, 0, mSize.height * mStride);
+        if (aClear)
+            memset(mData, 0, mSize.height * mStride);
     }
 
     mOwnsData = true;

gfx/thebes/gfxImageSurface.h

@@ -71,7 +71,7 @@ public:
      *
      * @see gfxImageFormat
      */
-    gfxImageSurface(const gfxIntSize& size, gfxImageFormat format);
+    gfxImageSurface(const gfxIntSize& size, gfxImageFormat format, bool aClear = true);
     gfxImageSurface(cairo_surface_t *csurf);
 
     virtual ~gfxImageSurface();