modules/video_coding refactorings

The main purpose was the interface-> include rename, but other files
were also moved, eliminating the "main" dir.

To avoid breaking downstream, the "interface" directories were copied
into a new "video_coding/include" dir. The old headers got pragma
warnings added about deprecation (a very short deprecation since I plan
to remove them as soon downstream is updated).

Other files also moved:
video_coding/main/source -> video_coding
video_coding/main/test -> video_coding/test

BUG=webrtc:5095
TESTED=Passing compile-trybots with --clobber flag:
git cl try --clobber --bot=win_compile_rel --bot=linux_compile_rel --bot=android_compile_rel --bot=mac_compile_rel --bot=ios_rel --bot=linux_gn_rel --bot=win_x64_gn_rel --bot=mac_x64_gn_rel --bot=android_gn_rel -m tryserver.webrtc

R=stefan@webrtc.org, tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1417283007 .

Cr-Commit-Position: refs/heads/master@{#10694}

webrtc/modules/video_coding/test/subfigure.m

@@ -0,0 +1,30 @@
+function H = subfigure(m, n, p)
+%
+% H = SUBFIGURE(m, n, p)
+%
+% Create a new figure window and adjust position and size such that it will
+% become the p-th tile in an m-by-n matrix of windows. (The interpretation of
+% m, n, and p is the same as for SUBPLOT.
+%
+% Henrik Lundin, 2009-01-19
+%
+
+
+h = figure;
+
+[j, i] = ind2sub([n m], p);
+scrsz = get(0,'ScreenSize'); % get screen size
+%scrsz = [1, 1, 1600, 1200];
+
+taskbarSize = 58;
+windowbarSize = 68;
+windowBorder = 4;
+
+scrsz(2) = scrsz(2) + taskbarSize;
+scrsz(4) = scrsz(4) - taskbarSize;
+
+set(h, 'position', [(j-1)/n * scrsz(3) + scrsz(1) + windowBorder,...
+        (m-i)/m * scrsz(4) + scrsz(2) + windowBorder, ...
+        scrsz(3)/n - (windowBorder + windowBorder),...
+        scrsz(4)/m - (windowbarSize + windowBorder + windowBorder)]);
+