Have peek32 return uint32_t& to make it harder to look at more than 4 bytes.

src/core/SkWriteBuffer.cpp

Index: src/core/SkWriteBuffer.cpp
diff --git a/src/core/SkWriteBuffer.cpp b/src/core/SkWriteBuffer.cpp
index cbbb4c94fc1926bca82ac18f2fd661a1802678d3..b1b029adb4baf9ae87b729ae8ca07c35c0f30295 100644
--- a/src/core/SkWriteBuffer.cpp
+++ b/src/core/SkWriteBuffer.cpp
@@ -321,5 +321,5 @@ void SkWriteBuffer::writeFlattenable(const SkFlattenable* flattenable) {
     flattenable->flatten(*this);
     uint32_t objSize = fWriter.bytesWritten() - offset;
     // record the obj's size
-    *fWriter.peek32(offset - sizeof(uint32_t)) = objSize;
+    fWriter.peek32(offset - sizeof(uint32_t)) = objSize;
 }