Update old tools to allow MultiPictureDraw rendering

I'll post a separate patch for nanobench and dm

Review URL: https://codereview.chromium.org/639013003
diff --git a/tools/render_pictures_main.cpp b/tools/render_pictures_main.cpp
index d7a213c..6faa81a 100644
--- a/tools/render_pictures_main.cpp
+++ b/tools/render_pictures_main.cpp
@@ -40,7 +40,7 @@
 DEFINE_bool(gpuStats, false, "Only meaningful with gpu configurations. "
             "Report some GPU call statistics.");
 #endif
-DEFINE_bool(preprocess, false, "If true, perform device specific preprocessing before rendering.");
+DEFINE_bool(mpd, false, "If true, use MultiPictureDraw for rendering.");
 DEFINE_string(readJsonSummaryPath, "", "JSON file to read image expectations from.");
 DECLARE_string(readPath);
 DEFINE_bool(writeChecksumBasedFilenames, false,
@@ -184,16 +184,6 @@
         return false;
     }
 
-    if (FLAGS_preprocess) {
-        // Because the GPU preprocessing step relies on the in-memory picture
-        // statistics we need to rerecord the picture here
-        SkPictureRecorder recorder;
-        picture->playback(recorder.beginRecording(picture->cullRect().width(), 
-                                                  picture->cullRect().height(), 
-                                                  NULL, 0));
-        picture.reset(recorder.endRecording());
-    }
-
     while (FLAGS_bench_record) {
         SkPictureRecorder recorder;
         picture->playback(recorder.beginRecording(picture->cullRect().width(), 
@@ -208,13 +198,7 @@
              inputPath.c_str());
 
     renderer.init(picture, &writePathString, &mismatchPathString, &inputFilename,
-                  FLAGS_writeChecksumBasedFilenames);
-
-    if (FLAGS_preprocess) {
-        if (renderer.getCanvas()) {
-            renderer.getCanvas()->EXPERIMENTAL_optimize(renderer.getPicture());
-        }
-    }
+                  FLAGS_writeChecksumBasedFilenames, FLAGS_mpd);
 
     renderer.setup();
     renderer.enableWrites();