Avoid regenerating cached textblobs on integer scrolls

src/gpu/GrTextBlobCache.cpp

Index: src/gpu/GrTextBlobCache.cpp
diff --git a/src/gpu/GrTextBlobCache.cpp b/src/gpu/GrTextBlobCache.cpp
index 574cc72e4feb70445d81cc662e6de9fc6271a416..9141b1712ad67c26c3f32360bb3dd01dc3208b37 100644
--- a/src/gpu/GrTextBlobCache.cpp
+++ b/src/gpu/GrTextBlobCache.cpp
@@ -9,6 +9,14 @@
 
 static const int kVerticesPerGlyph = 4;
 
+GrTextBlobCache::~GrTextBlobCache() {
+    SkTDynamicHash<BitmapTextBlob, uint32_t>::Iter iter(&fCache);
+    while (!iter.done()) {
+        (&(*iter))->unref();
+        ++iter;
+    }
+}
+
 GrAtlasTextContext::BitmapTextBlob* GrTextBlobCache::createBlob(int glyphCount, int runCount,
                                                                 size_t maxVASize) {
     // We allocate size for the BitmapTextBlob itself, plus size for the vertices array,
@@ -32,7 +40,6 @@ GrAtlasTextContext::BitmapTextBlob* GrTextBlobCache::createBlob(int glyphCount,
         SkNEW_PLACEMENT(&cacheBlob->fRuns[i], BitmapTextBlob::Run);
     }
     cacheBlob->fRunCount = runCount;
-    cacheBlob->fSize = size;
     cacheBlob->fPool = &fPool;
     return cacheBlob;
 }