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

This allows internal Gr texture creation code to succeed for extraneous textures while running the bleed GM. This means we can turn on the shader variants.

Review URL: https://codereview.chromium.org/1418473004
diff --git a/src/gpu/GrCaps.cpp b/src/gpu/GrCaps.cpp
index 4095f1a..75cecdf 100644
--- a/src/gpu/GrCaps.cpp
+++ b/src/gpu/GrCaps.cpp
@@ -121,6 +121,12 @@
 
 void GrCaps::applyOptionsOverrides(const GrContextOptions& options) {
     fMaxTextureSize = SkTMin(fMaxTextureSize, options.fMaxTextureSizeOverride);
+    // If the max tile override is zero, it means we should use the max texture size.
+    if (!options.fMaxTileSizeOverride || options.fMaxTileSizeOverride > fMaxTextureSize) {
+        fMaxTileSize = fMaxTextureSize;
+    } else {
+        fMaxTileSize = options.fMaxTileSizeOverride;
+    }
 }
 
 static SkString map_flags_to_string(uint32_t flags) {