Add GlyphMetricsMap memory consumption to memory-infra tracing

third_party/WebKit/Source/platform/fonts/SimpleFontData.h

Index: third_party/WebKit/Source/platform/fonts/SimpleFontData.h
diff --git a/third_party/WebKit/Source/platform/fonts/SimpleFontData.h b/third_party/WebKit/Source/platform/fonts/SimpleFontData.h
index 9cbeb8b371988ab6d39cf1ab155293a2773d26e4..cc9452304067fce8185b8ebedf6db11feb3b2df4 100644
--- a/third_party/WebKit/Source/platform/fonts/SimpleFontData.h
+++ b/third_party/WebKit/Source/platform/fonts/SimpleFontData.h
@@ -127,6 +127,13 @@ public:
     // Implemented by the platform.
     virtual bool fillGlyphPage(GlyphPage* pageToFill, unsigned offset, unsigned length, UChar* buffer, unsigned bufferLength) const;
 
+    size_t glyphToBoundsMapMemorySize()
+    {
+        if (!m_glyphToBoundsMap)
+            return 0;
+        return m_glyphToBoundsMap->memoryUsageInBytes();
+    }
+
 protected:
     SimpleFontData(const FontPlatformData&, PassRefPtr<CustomFontData> customData, bool isTextOrientationFallback = false);