Make HarfBuzzFace release SimpleFontData.

third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzFace.cpp

Index: third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzFace.cpp
diff --git a/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzFace.cpp b/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzFace.cpp
index cb2aae1b0a5bd47394d9f53dd3c010bf7bde6006..5c1a7e50a31d0ea12bcc70c12ddf7f7203cfeedb 100644
--- a/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzFace.cpp
+++ b/third_party/WebKit/Source/platform/fonts/shaping/HarfBuzzFace.cpp
@@ -84,6 +84,21 @@ struct HarfBuzzFontData {
   HarfBuzzFontData()
       : m_paint(), m_simpleFontData(nullptr), m_rangeSet(nullptr) {}
 
+  ~HarfBuzzFontData() {
+    if (m_simpleFontData)
+      FontCache::fontCache()->releaseFontData(m_simpleFontData);
+  }
+
+  void updateSimpleFontData(FontPlatformData* platformData) {
+    SimpleFontData* simpleFontData =
+        FontCache::fontCache()
+            ->fontDataFromFontPlatformData(platformData)
+            .get();
+    if (m_simpleFontData)

[drott, 2016/10/13 07:28:34]

I think in the else case we need to release the new simpleFontData, don't we?

Or, alternatively, compare 
m_simpleFontData->platformData().size() to platformData.size() and only lookup a
new one from the cache if they differ. If all LayoutTests pass after that, this
should be fine, too.

[jb, 2016/10/13 07:53:47]

I think you misread the code. I always release the old one. If there is no
change, then releasing the old one has the same effect as releasing the new one,
so the counter is balanced either way.

[drott, 2016/10/13 08:06:29]

True, sorry.

+      FontCache::fontCache()->releaseFontData(m_simpleFontData);
+    m_simpleFontData = simpleFontData;
+  }
+
   SkPaint m_paint;
   SimpleFontData* m_simpleFontData;
   RefPtr<UnicodeRangeSet> m_rangeSet;
@@ -370,10 +385,7 @@ hb_font_t* HarfBuzzFace::getScaledFont(
   m_platformData->setupPaint(&m_harfBuzzFontData->m_paint);
   m_harfBuzzFontData->m_paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
   m_harfBuzzFontData->m_rangeSet = rangeSet;
-  m_harfBuzzFontData->m_simpleFontData =
-      FontCache::fontCache()
-          ->fontDataFromFontPlatformData(m_platformData)
-          .get();
+  m_harfBuzzFontData->updateSimpleFontData(m_platformData);
   ASSERT(m_harfBuzzFontData->m_simpleFontData);
   int scale = SkiaScalarToHarfBuzzPosition(m_platformData->size());
   hb_font_set_scale(m_unscaledFont, scale, scale);