Rename the shared impl files.

ppapi/shared_impl/ppb_font_shared.cc

Index: ppapi/shared_impl/ppb_font_shared.cc
diff --git a/ppapi/shared_impl/font_impl.cc b/ppapi/shared_impl/ppb_font_shared.cc
similarity index 87%
rename from ppapi/shared_impl/font_impl.cc
rename to ppapi/shared_impl/ppb_font_shared.cc
index 66ac5a61e427ee63da021d8ea5b54410b5e065b5..a714643028ff62d204e7cc0b7d2600bae44e1dde 100644
--- a/ppapi/shared_impl/font_impl.cc
+++ b/ppapi/shared_impl/ppb_font_shared.cc
@@ -2,14 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ppapi/shared_impl/font_impl.h"
+#include "ppapi/shared_impl/ppb_font_shared.h"
 
 #include "ppapi/c/dev/ppb_font_dev.h"
 
 namespace ppapi {
 
 // static
-bool FontImpl::IsPPFontDescriptionValid(const PP_FontDescription_Dev& desc) {
+bool PPB_Font_Shared::IsPPFontDescriptionValid(
+    const PP_FontDescription_Dev& desc) {
   // Check validity of string. We can't check the actual text since we could
   // be on the wrong thread and don't know if we're in the plugin or the host.
   if (desc.face.type != PP_VARTYPE_STRING &&