Allow max tile size to be overridden separately from max texture size.

include/gpu/GrContextOptions.h

Index: include/gpu/GrContextOptions.h
diff --git a/include/gpu/GrContextOptions.h b/include/gpu/GrContextOptions.h
index 4b70105559fa1a9dcdadfae486be4497d7eed6ed..5619e3063b8ff3a127e30f0c00e83d9311262eab 100644
--- a/include/gpu/GrContextOptions.h
+++ b/include/gpu/GrContextOptions.h
@@ -15,6 +15,7 @@ struct GrContextOptions {
         : fDrawPathToCompressedTexture(false)
         , fSuppressPrints(false)
         , fMaxTextureSizeOverride(SK_MaxS32)
+        , fMaxTileSizeOverride(0)
         , fSuppressDualSourceBlending(false)
         , fGeometryBufferMapThreshold(-1)
         , fUseDrawInsteadOfPartialRenderTargetWrite(false)
@@ -33,6 +34,9 @@ struct GrContextOptions {
         detected values. */
 
     int  fMaxTextureSizeOverride;
+    /** If non-zero, overrides the maximum size of a tile for sw-backed images and bitmaps rendered
+        by SkGpuDevice. */
+    int  fMaxTileSizeOverride;
     bool fSuppressDualSourceBlending;
 
     /** the threshold in bytes above which we will use a buffer mapping API to map vertex and index