Linux: Add support for chrooted renderers.

skia/ext/SkFontHost_fontconfig_ipc.h

+/* libs/graphics/ports/SkFontHost_fontconfig_direct.h
+**
+** Copyright 2009, Google Inc.
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#ifndef FontConfigIPC_DEFINED
+#define FontConfigIPC_DEFINED
+
+// http://code.google.com/p/chromium/wiki/LinuxSandboxIPC
+
+#include <map>
+#include <string>
+
+#include "SkFontHost_fontconfig_impl.h"
+
+class FontConfigIPC : public FontConfigInterface {
+  public:
+    FontConfigIPC(int fd);
+    ~FontConfigIPC();
+
+    // FontConfigInterface implementation.
+    virtual bool Match(std::string* result_family, unsigned* result_fileid,
+                       bool fileid_valid, unsigned fileid,
+                       const std::string& family, int is_bold, int is_italic);
+    virtual int Open(unsigned fileid);
+
+    enum Method {
+        METHOD_MATCH = 0,
+        METHOD_OPEN = 1,
+    };
+
+    struct MatchRequest {
+        uint16_t method;
+        uint8_t fileid_valid;
+        uint32_t fileid;
+        int8_t is_bold;
+        int8_t is_italic;
+        uint8_t family_len;
+        // char family[0] follows.
+    };
+
+    struct MatchReply {
+        uint8_t result;
+        uint32_t result_fileid;
+        uint16_t filename_len;
+        // char filename[0] follows.
+    };
+
+    struct OpenRequest {
+        uint16_t method;
+        unsigned fileid;
+    };
+
+    struct OpenReply {
+        uint8_t result;
+    };
+
+  private:
+    const int fd_;
+};
+
+#endif  // FontConfigIPC_DEFINED