Remove a linear search in SkPictureRecord::addTextBlob.

src/core/SkPictureRecord.cpp

Index: src/core/SkPictureRecord.cpp
diff --git a/src/core/SkPictureRecord.cpp b/src/core/SkPictureRecord.cpp
index a6b6f613933daba03dd0a8dc1a57ba3db5c1dbd2..b17169183a1a71bd41fde3e8c22ba352f78d3f68 100644
--- a/src/core/SkPictureRecord.cpp
+++ b/src/core/SkPictureRecord.cpp
@@ -1544,12 +1544,9 @@ void SkPictureRecord::addText(const void* text, size_t byteLength) {
 }
 
 void SkPictureRecord::addTextBlob(const SkTextBlob *blob) {
-    int index = fTextBlobRefs.find(blob);
-    if (index < 0) {    // not found
-        index = fTextBlobRefs.count();
-        *fTextBlobRefs.append() = blob;
-        blob->ref();
-    }
+    int index = fTextBlobRefs.count();
+    *fTextBlobRefs.append() = blob;
+    blob->ref();
     // follow the convention of recording a 1-based index
     this->addInt(index + 1);
 }