ccpr: Prefer atlas sizes under 4k on ARM

Bug: skia:
Change-Id: Ib5afb84647efe2e64a3ec2f9da422b39228431e9
Reviewed-on: https://skia-review.googlesource.com/108871
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/mock/GrMockCaps.h b/src/gpu/mock/GrMockCaps.h
index d96a690..e75a2c6 100644
--- a/src/gpu/mock/GrMockCaps.h
+++ b/src/gpu/mock/GrMockCaps.h
@@ -20,6 +20,7 @@
         fBufferMapThreshold = SK_MaxS32; // Overridable in GrContextOptions.
         fMaxTextureSize = options.fMaxTextureSize;
         fMaxRenderTargetSize = SkTMin(options.fMaxRenderTargetSize, fMaxTextureSize);
+        fMaxPreferredRenderTargetSize = fMaxRenderTargetSize;
         fMaxVertexAttributes = options.fMaxVertexAttributes;
 
         fShaderCaps.reset(new GrShaderCaps(contextOptions));