Add support for light dumps in SkTraceMemoryDump interface.

src/core/SkGlyphCache.cpp

Index: src/core/SkGlyphCache.cpp
diff --git a/src/core/SkGlyphCache.cpp b/src/core/SkGlyphCache.cpp
index 309707c66fede82e8ee775b7d545b3984e44001f..7cc4ebb26301df12c4a5c217b2ae0bdd3b992052 100644
--- a/src/core/SkGlyphCache.cpp
+++ b/src/core/SkGlyphCache.cpp
@@ -451,6 +451,11 @@ void SkGlyphCache::DumpMemoryStatistics(SkTraceMemoryDump* dump) {
     dump->dumpNumericValue(gGlyphCacheDumpName, "budget_glyph_count", "objects",
                            SkGraphics::GetFontCacheCountLimit());
 
+    if (dump->isLightDump()) {
+      dump->setMemoryBacking(gGlyphCacheDumpName, "malloc", nullptr);
+      return;
+    }
+
     int counter = 0;
     SkGlyphCacheDumpContext context = { &counter, dump };
     SkGlyphCache::VisitAll(sk_trace_dump_visitor, &context);