base: Fix an inefficiency in base::Pickle that caused extraneous allocations.

base/pickle.cc

Index: base/pickle.cc
diff --git a/base/pickle.cc b/base/pickle.cc
index d4487d45b24d61238309d3db48b1f17f4f2e0cca..a7cfae57bd96a51834f7da9717d7d4157f06447e 100644
--- a/base/pickle.cc
+++ b/base/pickle.cc
@@ -254,8 +254,8 @@ Pickle::Pickle(const Pickle& other)
       header_size_(other.header_size_),
       capacity_after_header_(0),
       write_offset_(other.write_offset_) {
+  Resize(other.header_->payload_size);
   size_t payload_size = header_size_ + other.header_->payload_size;

[Mark Mentovai, 2015/09/08 23:25:17]

This isn’t useful as a standalone variable now, you can do the addition right in
the memcpy() argument. (That’ll keep it more similar to operator=.)

[erikchen, 2015/09/08 23:33:39]

Done.

-  Resize(payload_size);
   memcpy(header_, other.header_, payload_size);
 }