Add compile time checks against longs being used in IPC structs on 32 bit Android.

base/pickle.h

Index: base/pickle.h
diff --git a/base/pickle.h b/base/pickle.h
index 02bc432ad0bd27564e289f9d8fae0b9ca9408241..7fb680614e843077fc9b9d18d803ca6d54e4627d 100644
--- a/base/pickle.h
+++ b/base/pickle.h
@@ -173,13 +173,10 @@ class BASE_EXPORT Pickle {
   bool WriteInt(int value) {
     return WritePOD(value);
   }
-  // WARNING: DO NOT USE THIS METHOD IF PICKLES ARE PERSISTED IN ANY WAY.
-  // It will write whatever a "long" is on this architecture. On 32-bit
-  // platforms, it is 32 bits. On 64-bit platforms, it is 64 bits. If persisted
-  // pickles are still around after upgrading to 64-bit, or if they are copied
-  // between dissimilar systems, YOUR PICKLES WILL HAVE GONE BAD.
-  bool WriteLongUsingDangerousNonPortableLessPersistableForm(long value) {
-    return WritePOD(value);
+  bool WriteLong(long value) {
+    // Always write long as a 64-bit value to ensure compatibility between
+    // 32-bit and 64-bit processes.
+    return WritePOD(static_cast<int64_t>(value));
   }
   bool WriteUInt16(uint16_t value) { return WritePOD(value); }
   bool WriteUInt32(uint32_t value) { return WritePOD(value); }