Reduce the minimum scratch size to 16, don't look for next pow2 larger sizes.

src/gpu/GrContext.cpp

Index: src/gpu/GrContext.cpp
===================================================================
--- src/gpu/GrContext.cpp	(revision 8005)
+++ src/gpu/GrContext.cpp	(working copy)
@@ -428,7 +428,7 @@
 
     if (kApprox_ScratchTexMatch == match) {
         // bin by pow2 with a reasonable min
-        static const int MIN_SIZE = 256;
+        static const int MIN_SIZE = 16;
         desc.fWidth  = GrMax(MIN_SIZE, GrNextPow2(desc.fWidth));
         desc.fHeight = GrMax(MIN_SIZE, GrNextPow2(desc.fHeight));
     }
@@ -455,23 +455,13 @@
         if (kExact_ScratchTexMatch == match) {
             break;
         }
-        // We had a cache miss and we are in approx mode, relax the fit of the flags... then try
-        // doubling width... then the height.
+        // We had a cache miss and we are in approx mode, relax the fit of the flags.
 
         // We no longer try to reuse textures that were previously used as render targets in
         // situations where no RT is needed; doing otherwise can confuse the video driver and
         // cause significant performance problems in some cases.
         if (desc.fFlags & kNoStencil_GrTextureFlagBit) {
             desc.fFlags = desc.fFlags & ~kNoStencil_GrTextureFlagBit;
-        } else if (!doubledW) {
-            desc.fFlags = inDesc.fFlags;
-            desc.fWidth *= 2;
-            doubledW = true;
-        } else if (!doubledH) {
-            desc.fFlags = inDesc.fFlags;
-            desc.fWidth = origWidth;
-            desc.fHeight *= 2;
-            doubledH = true;
         } else {
             break;
         }