clang plugin: Remove follow-macro-expansion toggle

It has been enabled by default since
https://codereview.chromium.org/1529323002/

BUG=156590

Review-Url: https://codereview.chromium.org/2265093002
Cr-Commit-Position: refs/heads/master@{#413461}

tools/clang/plugins/ChromeClassTester.cpp

@@ -197,30 +197,20 @@ bool ChromeClassTester::HasIgnoredBases(const CXXRecordDecl* record) {
 bool ChromeClassTester::InImplementationFile(SourceLocation record_location) {
   std::string filename;
 
-  if (options_.follow_macro_expansion) {
-    // If |record_location| is a macro, check the whole chain of expansions.
-    const SourceManager& source_manager = instance_.getSourceManager();
-    while (true) {
-      if (GetFilename(record_location, &filename)) {
-        if (ends_with(filename, ".cc") || ends_with(filename, ".cpp") ||
-            ends_with(filename, ".mm")) {
-          return true;
-        }
-      }
-      if (!record_location.isMacroID()) {
-        break;
+  // If |record_location| is a macro, check the whole chain of expansions.
+  const SourceManager& source_manager = instance_.getSourceManager();
+  while (true) {
+    if (GetFilename(record_location, &filename)) {
+      if (ends_with(filename, ".cc") || ends_with(filename, ".cpp") ||
+          ends_with(filename, ".mm")) {
+        return true;
       }
-      record_location =
-          source_manager.getImmediateExpansionRange(record_location).first;
     }
-  } else {
-    if (!GetFilename(record_location, &filename))
-      return false;
-
-    if (ends_with(filename, ".cc") || ends_with(filename, ".cpp") ||
-        ends_with(filename, ".mm")) {
-      return true;
+    if (!record_location.isMacroID()) {
+      break;
     }
+    record_location =
+        source_manager.getImmediateExpansionRange(record_location).first;
   }
 
   return false;

tools/clang/plugins/FindBadConstructsAction.cpp

@@ -58,7 +58,8 @@ bool FindBadConstructsAction::ParseArgs(const CompilerInstance& instance,
     } else if (args[i] == "check-templates") {
       options_.check_templates = true;
     } else if (args[i] == "follow-macro-expansion") {
-      options_.follow_macro_expansion = true;
+      // TODO(thakis): This is now always on. Remove support for this flag once
+      // the build no longer passes it in.
     } else if (args[i] == "no-realpath") {
       options_.no_realpath = true;
     } else if (args[i] == "check-ipc") {

tools/clang/plugins/Options.h

@@ -13,7 +13,6 @@ struct Options {
   bool enforce_in_thirdparty_webkit = false;  // Use in Blink code itself
   bool check_enum_last_value = false;
   bool check_templates = false;
-  bool follow_macro_expansion = false;
   // This is needed for some distributed build-sytems to respect banned
   // paths. See https://crbug.com/583454 for details.
   bool no_realpath = false;