Revert of Fix for the font files being maped multiple times (Fontconfig).

content/common/font_config_ipc_linux.cc

Index: content/common/font_config_ipc_linux.cc
diff --git a/content/common/font_config_ipc_linux.cc b/content/common/font_config_ipc_linux.cc
index f24e06caeaafe1a0e2135475052668e1a75d733c..c64aebf66a57fa3c432646d1906e5a15bf12b2ef 100644
--- a/content/common/font_config_ipc_linux.cc
+++ b/content/common/font_config_ipc_linux.cc
@@ -14,11 +14,8 @@
 
 #include "base/debug/trace_event.h"
 #include "base/files/file_util.h"
-#include "base/files/memory_mapped_file.h"
-#include "base/memory/ref_counted.h"
 #include "base/pickle.h"
 #include "base/posix/unix_domain_socket_linux.h"
-#include "base/threading/thread_restrictions.h"
 #include "skia/ext/refptr.h"
 #include "skia/ext/skia_utils_base.h"
 #include "third_party/skia/include/core/SkData.h"
@@ -26,45 +23,14 @@
 
 namespace content {
 
-class FontConfigIPC::MappedFontFile
-    : public base::RefCountedThreadSafe<MappedFontFile> {
- public:
-  explicit MappedFontFile(uint32_t font_id) : font_id_(font_id) {}
-
-  uint32_t font_id() const { return font_id_; }
-
-  bool Initialize(int fd) {
-    base::ThreadRestrictions::ScopedAllowIO allow_mmap;
-    return mapped_font_file_.Initialize(base::File(fd));
+// Return a stream from the file descriptor, or NULL on failure.
+SkStream* StreamFromFD(int fd) {
+  skia::RefPtr<SkData> data = skia::AdoptRef(SkData::NewFromFD(fd));
+  if (!data) {
+    return NULL;
   }
-
-  SkMemoryStream* CreateMemoryStream() {
-    DCHECK(mapped_font_file_.IsValid());
-    auto data = skia::AdoptRef(SkData::NewWithProc(
-        mapped_font_file_.data(), mapped_font_file_.length(),
-        &MappedFontFile::ReleaseProc, this));
-    if (!data)
-      return nullptr;
-    AddRef();
-    return new SkMemoryStream(data.get());
-  }
-
- private:
-  friend class base::RefCountedThreadSafe<MappedFontFile>;
-
-  ~MappedFontFile() {
-    auto font_config = static_cast<FontConfigIPC*>(FontConfigIPC::RefGlobal());
-    font_config->RemoveMappedFontFile(this);
-  }
-
-  static void ReleaseProc(const void* ptr, size_t length, void* context) {
-    base::ThreadRestrictions::ScopedAllowIO allow_munmap;
-    static_cast<MappedFontFile*>(context)->Release();
-  }
-
-  uint32_t font_id_;
-  base::MemoryMappedFile mapped_font_file_;
-};
+  return new SkMemoryStream(data.get());
+}
 
 void CloseFD(int fd) {
   int err = IGNORE_EINTR(close(fd));
@@ -130,14 +96,6 @@
 
 SkStream* FontConfigIPC::openStream(const FontIdentity& identity) {
   TRACE_EVENT0("sandbox_ipc", "FontConfigIPC::openStream");
-
-  {
-    base::AutoLock lock(lock_);
-    auto mapped_font_files_it = mapped_font_files_.find(identity.fID);
-    if (mapped_font_files_it != mapped_font_files_.end())
-      return mapped_font_files_it->second->CreateMemoryStream();
-  }
-
   Pickle request;
   request.WriteInt(METHOD_OPEN);
   request.WriteUInt32(identity.fID);
@@ -160,23 +118,9 @@
     return NULL;
   }
 
-  scoped_refptr<MappedFontFile> mapped_font_file =
-      new MappedFontFile(identity.fID);
-  if (!mapped_font_file->Initialize(result_fd))
-    return nullptr;
-
-  {
-    base::AutoLock lock(lock_);
-    auto mapped_font_files_it =
-        mapped_font_files_.insert(std::make_pair(mapped_font_file->font_id(),
-                                                 mapped_font_file.get())).first;
-    return mapped_font_files_it->second->CreateMemoryStream();
-  }
-}
-
-void FontConfigIPC::RemoveMappedFontFile(MappedFontFile* mapped_font_file) {
-  base::AutoLock lock(lock_);
-  mapped_font_files_.erase(mapped_font_file->font_id());
+  SkStream* stream = StreamFromFD(result_fd);
+  CloseFD(result_fd);
+  return stream;
 }
 
 }  // namespace content