Try to get clang plugin compiling again after upstream r331155.

While here, also s/LLVM_ON_WIN32/_WIN32/ since LLVM_ON_WIN32 is going
away and _WIN32 is the same thing.

Bug: none
Change-Id: I64f813b4d4c488fbd9ff7601416e29b4b1973a10
Reviewed-on: https://chromium-review.googlesource.com/1035103
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554755}

tools/clang/blink_gc_plugin/BlinkGCPluginConsumer.cpp

@@ -711,7 +711,7 @@ bool BlinkGCPluginConsumer::InIgnoredDirectory(RecordInfo* info) {
   std::string filename;
   if (!GetFilename(info->record()->getLocStart(), &filename))
     return false;  // TODO: should we ignore non-existing file locations?
-#if defined(LLVM_ON_WIN32)
+#if defined(_WIN32)
   std::replace(filename.begin(), filename.end(), '\\', '/');
 #endif
   for (const auto& dir : options_.ignored_directories)

tools/clang/plugins/ChromeClassTester.cpp

@@ -17,7 +17,7 @@
 #ifdef LLVM_ON_UNIX
 #include <sys/param.h>
 #endif
-#if defined(LLVM_ON_WIN32)
+#if defined(_WIN32)
 #include <windows.h>
 #endif
 
@@ -154,7 +154,11 @@ bool ChromeClassTester::InImplementationFile(SourceLocation record_location) {
       break;
     }
     record_location =
+#if defined(LLVM_FORCE_HEAD_REVISION)
+        source_manager.getImmediateExpansionRange(record_location).getBegin();
+#else
         source_manager.getImmediateExpansionRange(record_location).first;
+#endif
   }
 
   return false;