Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/src/google/protobuf/compiler/importer.cc

Index: third_party/protobuf/src/google/protobuf/compiler/importer.cc
diff --git a/third_party/protobuf/src/google/protobuf/compiler/importer.cc b/third_party/protobuf/src/google/protobuf/compiler/importer.cc
index 8333684e1ba56a9d4e3fe52d485632f0b9b6ac32..422f759f2be75b21881f3591cef5cbd525b07a5b 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/importer.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/importer.cc
@@ -1,6 +1,6 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
+// http://code.google.com/p/protobuf/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,10 +43,6 @@
 #include <errno.h>
 
 #include <algorithm>
-#include <memory>
-#ifndef _SHARED_PTR_H
-#include <google/protobuf/stubs/shared_ptr.h>
-#endif
 
 #include <google/protobuf/compiler/importer.h>
 
@@ -125,11 +121,10 @@ SourceTreeDescriptorDatabase::~SourceTreeDescriptorDatabase() {}
 
 bool SourceTreeDescriptorDatabase::FindFileByName(
     const string& filename, FileDescriptorProto* output) {
-  google::protobuf::scoped_ptr<io::ZeroCopyInputStream> input(source_tree_->Open(filename));
+  scoped_ptr<io::ZeroCopyInputStream> input(source_tree_->Open(filename));
   if (input == NULL) {
     if (error_collector_ != NULL) {
-      error_collector_->AddError(filename, -1, 0,
-                                 source_tree_->GetLastErrorMessage());
+      error_collector_->AddError(filename, -1, 0, "File not found.");
     }
     return false;
   }
@@ -191,7 +186,6 @@ Importer::Importer(SourceTree* source_tree,
                    MultiFileErrorCollector* error_collector)
   : database_(source_tree),
     pool_(&database_, database_.GetValidationErrorCollector()) {
-  pool_.EnforceWeakDependencies(true);
   database_.RecordErrorsTo(error_collector);
 }
 
@@ -201,22 +195,10 @@ const FileDescriptor* Importer::Import(const string& filename) {
   return pool_.FindFileByName(filename);
 }
 
-void Importer::AddUnusedImportTrackFile(const string& file_name) {
-  pool_.AddUnusedImportTrackFile(file_name);
-}
-
-void Importer::ClearUnusedImportTrackFiles() {
-  pool_.ClearUnusedImportTrackFiles();
-}
-
 // ===================================================================
 
 SourceTree::~SourceTree() {}
 
-string SourceTree::GetLastErrorMessage() {
-  return "File not found.";
-}
-
 DiskSourceTree::DiskSourceTree() {}
 
 DiskSourceTree::~DiskSourceTree() {}
@@ -257,9 +239,9 @@ static string CanonicalizePath(string path) {
   }
 #endif
 
+  vector<string> parts;
   vector<string> canonical_parts;
-  vector<string> parts = Split(
-      path, "/", true);  // Note:  Removes empty parts.
+  SplitStringUsing(path, "/", &parts);  // Note:  Removes empty parts.
   for (int i = 0; i < parts.size(); i++) {
     if (parts[i] == ".") {
       // Ignore.
@@ -267,7 +249,7 @@ static string CanonicalizePath(string path) {
       canonical_parts.push_back(parts[i]);
     }
   }
-  string result = Join(canonical_parts, "/");
+  string result = JoinStrings(canonical_parts, "/");
   if (!path.empty() && path[0] == '/') {
     // Restore leading slash.
     result = '/' + result;
@@ -403,7 +385,7 @@ DiskSourceTree::DiskFileToVirtualFile(
   // Verify that we can open the file.  Note that this also has the side-effect
   // of verifying that we are not canonicalizing away any non-existent
   // directories.
-  google::protobuf::scoped_ptr<io::ZeroCopyInputStream> stream(OpenDiskFile(disk_file));
+  scoped_ptr<io::ZeroCopyInputStream> stream(OpenDiskFile(disk_file));
   if (stream == NULL) {
     return CANNOT_OPEN;
   }
@@ -413,8 +395,8 @@ DiskSourceTree::DiskFileToVirtualFile(
 
 bool DiskSourceTree::VirtualFileToDiskFile(const string& virtual_file,
                                            string* disk_file) {
-  google::protobuf::scoped_ptr<io::ZeroCopyInputStream> stream(
-      OpenVirtualFile(virtual_file, disk_file));
+  scoped_ptr<io::ZeroCopyInputStream> stream(OpenVirtualFile(virtual_file,
+                                                             disk_file));
   return stream != NULL;
 }
 
@@ -422,10 +404,6 @@ io::ZeroCopyInputStream* DiskSourceTree::Open(const string& filename) {
   return OpenVirtualFile(filename, NULL);
 }
 
-string DiskSourceTree::GetLastErrorMessage() {
-  return last_error_message_;
-}
-
 io::ZeroCopyInputStream* DiskSourceTree::OpenVirtualFile(
     const string& virtual_file,
     string* disk_file) {
@@ -434,8 +412,6 @@ io::ZeroCopyInputStream* DiskSourceTree::OpenVirtualFile(
     // We do not allow importing of paths containing things like ".." or
     // consecutive slashes since the compiler expects files to be uniquely
     // identified by file name.
-    last_error_message_ = "Backslashes, consecutive slashes, \".\", or \"..\" "
-                          "are not allowed in the virtual path";
     return NULL;
   }
 
@@ -453,13 +429,13 @@ io::ZeroCopyInputStream* DiskSourceTree::OpenVirtualFile(
 
       if (errno == EACCES) {
         // The file exists but is not readable.
-        last_error_message_ = "Read access is denied for file: " +
-                              temp_disk_file;
+        // TODO(kenton):  Find a way to report this more nicely.
+        GOOGLE_LOG(WARNING) << "Read access is denied for file: " << temp_disk_file;
         return NULL;
       }
     }
   }
-  last_error_message_ = "File not found.";
+
   return NULL;
 }