Reduce complexity of fake slide generator

The random square generator produces unrealistically complex frames in
some situations, leading to frames > 250kb even at max QP. This leads to
unmanageably long transmission delays.

Bug: None
Change-Id: I8f5a33d52fb5efa03de97e529ad598b75511f679
Reviewed-on: https://webrtc-review.googlesource.com/23561
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Stefan Holmer <stefan@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20912}
diff --git a/test/frame_generator.cc b/test/frame_generator.cc
index eb5e5d6..e5d9950 100644
--- a/test/frame_generator.cc
+++ b/test/frame_generator.cc
@@ -213,7 +213,7 @@
   void GenerateNewFrame() {
     // The squares should have a varying order of magnitude in order
     // to simulate variation in the slides' complexity.
-    const int kSquareNum =  1 << (4 + (random_generator_.Rand(0, 3) * 4));
+    const int kSquareNum =  1 << (4 + (random_generator_.Rand(0, 3) * 2));
 
     buffer_ = I420Buffer::Create(width_, height_);
     memset(buffer_->MutableDataY(), 127, height_ * buffer_->StrideY());