Check SkStream::isAtEnd before attempting to read.

src/utils/SkFrontBufferedStream.cpp

Index: src/utils/SkFrontBufferedStream.cpp
diff --git a/src/utils/SkFrontBufferedStream.cpp b/src/utils/SkFrontBufferedStream.cpp
index 8cb3931082c75d268e793212a73f688a1dbe227f..80a2bcfce32a2d27d2c7124c6117806b2548a11f 100644
--- a/src/utils/SkFrontBufferedStream.cpp
+++ b/src/utils/SkFrontBufferedStream.cpp
@@ -175,7 +175,7 @@ size_t FrontBufferedStream::read(void* voidDst, size_t size) {
 
     // Buffer any more data that should be buffered, and copy it to the
     // destination.
-    if (size > 0 && fBufferedSoFar < fBufferSize) {
+    if (size > 0 && fBufferedSoFar < fBufferSize && !fStream->isAtEnd()) {
         const size_t buffered = this->bufferAndWriteTo(dst, size);
 
         // Update the remaining number of bytes needed to read