fix more 64bit warnings

samplecode/SampleApp.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SampleApp.h"
 
 #include "SkData.h"
 #include "SkCanvas.h"
@@ skipping 110 matching lines @@
 }
 
 static const char* gPrefFileName = "sampleapp_prefs.txt";
 
 static bool readTitleFromPrefs(SkString* title) {
     SkFILEStream stream(gPrefFileName);
     if (!stream.isValid()) {
         return false;
     }
 
-    int len = stream.getLength();
+    size_t len = stream.getLength();
     SkString data(len);
     stream.read(data.writable_str(), len);
     const char* s = data.c_str();
 
     s = skip_past(s, "curr-slide-title");
     s = skip_past(s, "=");
     s = skip_past(s, "\"");
     const char* stop = skip_until(s, "\"");
     if (stop > s) {
         title->set(s, stop - s);
@@ skipping 2468 matching lines @@
     SkGraphics::Init();
     SkEvent::Init();
 }
 
 // FIXME: this should be in a header
 void application_term();
 void application_term() {
     SkEvent::Term();
     SkGraphics::Term();
 }