Linux: plumb fontconfig call out to the sandbox host.

chrome/browser/renderer_host/render_sandbox_host_linux.cc

Index: chrome/browser/renderer_host/render_sandbox_host_linux.cc
diff --git a/chrome/browser/renderer_host/render_sandbox_host_linux.cc b/chrome/browser/renderer_host/render_sandbox_host_linux.cc
index dcd20d9158d5849109aa95e2ff4931b697239638..e657af4088367f70bb9521243d9b44ff13d47372 100644
--- a/chrome/browser/renderer_host/render_sandbox_host_linux.cc
+++ b/chrome/browser/renderer_host/render_sandbox_host_linux.cc
@@ -15,11 +15,18 @@
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/pickle.h"
+#include "base/string_util.h"
 #include "base/unix_domain_socket_posix.h"
+#include "chrome/common/sandbox_methods_linux.h"
+#include "webkit/api/public/gtk/WebFontInfo.h"
 
 #include "SkFontHost_fontconfig_direct.h"
 #include "SkFontHost_fontconfig_ipc.h"
 
+using WebKit::WebFontInfo;
+using WebKit::WebString;
+using WebKit::WebUChar;
+
 // http://code.google.com/p/chromium/wiki/LinuxSandboxIPC
 
 // BEWARE: code in this file run across *processes* (not just threads).
@@ -101,6 +108,8 @@ class SandboxIPCProcess {
       HandleFontMatchRequest(fd, pickle, iter, fds);
     } else if (kind == FontConfigIPC::METHOD_OPEN) {
       HandleFontOpenRequest(fd, pickle, iter, fds);
+    } else if (kind == LinuxSandbox::METHOD_GET_FONT_FAMILY_FOR_CHARS) {
+      HandleGetFontFamilyForChars(fd, pickle, iter, fds);
     }
 
   error:
@@ -166,6 +175,43 @@ class SandboxIPCProcess {
     SendRendererReply(fds, reply, result_fd);
   }
 
+  void HandleGetFontFamilyForChars(int fd, Pickle& pickle, void* iter,
+                                   std::vector<int>& fds) {
+    // The other side of this call is
+    // chrome/renderer/renderer_sandbox_support_linux.cc
+
+    int num_chars;
+    if (!pickle.ReadInt(&iter, &num_chars))
+      return;
+
+    // We don't want a corrupt renderer asking too much of us, it might
+    // overflow later in the code.
+    static const int kMaxChars = 4096;
+    if (num_chars < 1 || num_chars > kMaxChars) {
+      LOG(WARNING) << "HandleGetFontFamilyForChars: too many chars: "
+                   << num_chars;
+      return;
+    }
+
+    scoped_array<WebUChar> chars(new WebUChar[num_chars]);
+
+    for (int i = 0; i < num_chars; ++i) {
+      uint32_t c;
+      if (!pickle.ReadUInt32(&iter, &c)) {
+        return;
+      }
+
+      chars[i] = c;
+    }
+
+    const WebString family = WebFontInfo::familyForChars(chars.get(), num_chars);
+    const std::string family_utf8 = UTF16ToUTF8(family);
+
+    Pickle reply;
+    reply.WriteString(family_utf8);
+    SendRendererReply(fds, reply, -1);
+  }
+
   void SendRendererReply(const std::vector<int>& fds, const Pickle& reply,
                          int reply_fd) {
     struct msghdr msg;