Add SyncSocket::ReceiveWithTimeout() and SyncSocket unit tests.

base/sync_socket.h

Index: base/sync_socket.h
diff --git a/base/sync_socket.h b/base/sync_socket.h
index 8ba3f6c2652f0a02e97066dae40f821387b253c3..71addd1e163a9ab16d201a961ba3ae5b3ed6972f 100644
--- a/base/sync_socket.h
+++ b/base/sync_socket.h
@@ -18,6 +18,7 @@
 #include "base/base_export.h"
 #include "base/compiler_specific.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/time/time.h"
 
 namespace base {
 
@@ -58,6 +59,13 @@ class BASE_EXPORT SyncSocket {
   // Returns the number of bytes received, or 0 upon failure.
   virtual size_t Receive(void* buffer, size_t length);
 
+  // Same as Receive() but only blocks for data until |timeout| has elapsed or
+  // |buffer| |length| is exhausted.  Currently only timeouts less than one
+  // second are allowed.  Return the amount of data read.
+  virtual size_t ReceiveWithTimeout(void* buffer,
+                                    size_t length,
+                                    TimeDelta timeout);
+
   // Returns the number of bytes available. If non-zero, Receive() will not
   // not block when called. NOTE: Some implementations cannot reliably
   // determine the number of bytes available so avoid using the returned
@@ -102,6 +110,9 @@ class BASE_EXPORT CancelableSyncSocket : public SyncSocket {
   // SyncSocket methods in order to support shutting down the 'socket'.
   virtual bool Close() OVERRIDE;
   virtual size_t Receive(void* buffer, size_t length) OVERRIDE;
+  virtual size_t ReceiveWithTimeout(void* buffer,
+                                    size_t length,
+                                    TimeDelta timeout) OVERRIDE;
 #endif
 
   // Send() is overridden to catch cases where the remote end is not responding