Remove unused RenderPassDrawQuad fields

The contents_changed_since_last_frame and is_replica fields are not
used. Also removes RenderSurfaceImpl's ContentsChanged() as this method
was only used in determining the value of
contents_changed_since_last_frame.

Unfortunately now RenderPassDrawQuad is only the largest quad type on
64-bit builds. So, adds kLargestQuadType to cc/quads/ and moves the
largest-quad-type unit test there verifying that kLargestQuadType is
the largest now, instead of RenderPassDrawQuad.

R=enne
BUG=401481
NOTRY=true

Review URL: https://codereview.chromium.org/448133002

Cr-Commit-Position: refs/heads/master@{#289091}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289091 0039d316-1c4b-4281-b951-d872f2087c98

diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 6a6cd02..f71a2d8 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn

@@ -289,6 +289,7 @@
     "quads/draw_quad.h",
     "quads/io_surface_draw_quad.cc",
     "quads/io_surface_draw_quad.h",
+    "quads/largest_draw_quad.h",
     "quads/picture_draw_quad.cc",
     "quads/picture_draw_quad.h",
     "quads/render_pass.cc",