Coverity: Fix a few uninitialized vars.

content/browser/renderer_host/render_sandbox_host_linux.cc

Index: content/browser/renderer_host/render_sandbox_host_linux.cc
diff --git a/content/browser/renderer_host/render_sandbox_host_linux.cc b/content/browser/renderer_host/render_sandbox_host_linux.cc
index ea40db23ef1113902fec87d152f3dea96edbb8f4..1ef5288ee7e50e74ad8e2d7b689dd02ef4cf7cd0 100644
--- a/content/browser/renderer_host/render_sandbox_host_linux.cc
+++ b/content/browser/renderer_host/render_sandbox_host_linux.cc
@@ -158,7 +158,7 @@ class SandboxIPCProcess  {
   void HandleFontMatchRequest(int fd, const Pickle& pickle, PickleIterator iter,
                               std::vector<int>& fds) {
     bool filefaceid_valid;
-    uint32_t filefaceid;
+    uint32_t filefaceid = 0;
 
     if (!pickle.ReadBool(&iter, &filefaceid_valid))
       return;