Add test for screen content coding tools in end to end test

Test screen content coding tools (currently only palette) at
speed 1 and two-pass.

Change-Id: I3c467aee1cd9c366c65a3abfdccfafa0416b59b7

test/vp9_end_to_end_test.cc

@@ -126,6 +126,11 @@ class EndToEndTestLarge
       encoder->Control(VP9E_SET_FRAME_PARALLEL_DECODING, 1);
       encoder->Control(VP9E_SET_TILE_COLUMNS, 4);
       encoder->Control(VP8E_SET_CPUUSED, cpu_used_);
+      // Test screen coding tools at cpu_used = 1 && encoding mode is two-pass.
+      if (cpu_used_ == 1 && encoding_mode_ == ::libvpx_test::kTwoPassGood)
+        encoder->Control(VP9E_SET_TUNE_CONTENT, VP9E_CONTENT_SCREEN);
+      else
+        encoder->Control(VP9E_SET_TUNE_CONTENT, VP9E_CONTENT_DEFAULT);
       if (encoding_mode_ != ::libvpx_test::kRealTime) {
         encoder->Control(VP8E_SET_ENABLEAUTOALTREF, 1);
         encoder->Control(VP8E_SET_ARNR_MAXFRAMES, 7);