Make not-reusing-scratch-textures only apply to texture uploads

src/gpu/GrDrawTargetCaps.h

Index: src/gpu/GrDrawTargetCaps.h
===================================================================
--- src/gpu/GrDrawTargetCaps.h	(revision 12025)
+++ src/gpu/GrDrawTargetCaps.h	(working copy)
@@ -37,6 +37,11 @@
     bool bufferLockSupport() const { return fBufferLockSupport; }
     bool pathRenderingSupport() const { return fPathRenderingSupport; }
     bool dstReadInShaderSupport() const { return fDstReadInShaderSupport; }
+
+    // Scratch textures not being reused means that those scratch textures
+    // that we upload to (i.e., don't have a render target) will not be 
+    // recycled in the texture cache. This is to prevent ghosting by drivers
+    // (in particular for deferred architectures).
     bool reuseScratchTextures() const { return fReuseScratchTextures; }
 
     int maxRenderTargetSize() const { return fMaxRenderTargetSize; }