Fix StrongAlias (de)serialization in IPC messages.

It currently uses
param_type::StrongAlias(..) to construct the type, which seems wrong
as param_type = util::StrongAlias<TagType, UnderlyingType>.
Which causes following compile error:

In file included from ../../ipc/ipc_message_utils_unittest.cc:5:
../../ipc/ipc_message_utils.h:1075:10: error: missing 'typename' prior to dependent type name 'param_type::StrongAlias'
    *r = param_type::StrongAlias(value);
         ^~~~~~~~~~~~~~~~~~~~~~~
Call StrongAlias constructor directly to fix this.
Add a regression unit test to fix the regression.

Bug: None
Change-Id: If172c83abd22498117c47a8721b7d9057c18a1d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1983570Reviewed-by: Ken Rockot <rockot@google.com>
Commit-Queue: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728702}

ipc/ipc_message_utils.h

@@ -1071,7 +1071,7 @@ struct ParamTraits<util::StrongAlias<TagType, UnderlyingType>> {
     UnderlyingType value;
     if (!ReadParam(m, iter, &value))
       return false;
-    *r = param_type::StrongAlias(value);
+    *r = param_type(value);
     return true;
   }
   static void Log(const param_type& p, std::string* l) {

ipc/ipc_message_utils_unittest.cc

@@ -216,5 +216,19 @@ TEST(IPCMessageUtilsTest, FlatMap) {
   EXPECT_EQ(input, output);
 }
 
+TEST(IPCMessageUtilsTest, StrongAlias) {
+  using TestType = util::StrongAlias<class Tag, int>;
+  TestType input(42);
+
+  base::Pickle pickle;
+  IPC::WriteParam(&pickle, input);
+
+  base::PickleIterator iter(pickle);
+  TestType output;
+  EXPECT_TRUE(IPC::ReadParam(&pickle, &iter, &output));
+
+  EXPECT_EQ(input, output);
+}
+
 }  // namespace
 }  // namespace IPC