Bug 1605283 - Improve support for invalidation debugging and testing …

…r=gw

Optionally serialize N frames into a circular memory buffer, and save
them as part of wr-capture into tilecache/.

The new tile_view utility reads the folder and converts the frames to
svg for easier visualization, with a few extra features:
- color code each primitive based on which slice it is on;
- highlight new or moving primitives in red (brute force diff);
- print all invalidated tiles at the top and the invalidation reason;
- overlay the tile quadtree to visualize splitting & merging;
- HTML and JS wrappers for animation playback, timeline scrubbing;

Positioning of the tiles on the screen is a bit broken still; especially
during scrolling and "special" pages (like about:config).

Interning info is not used yet.

Differential Revision: https://phabricator.services.mozilla.com/D59975

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/edd05995832f23464c115ca117146606cae15cde

Cargo.toml

@@ -6,6 +6,7 @@ members = [
     "webrender_api",
     "wrench",
     "example-compositor/compositor",
+    "tileview",
 ]
 
 [profile.release]

tileview/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "tileview"
+version = "0.1.0"
+authors = ["Bert Peers <bpeers@mozilla.com>"]
+license = "MPL-2.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+ron = "0.1.7"
+serde = {version = "1.0.88", features = ["derive"] }
+webrender = {path = "../webrender", features=["capture","replay","debugger","png","profiler","no_static_freetype", "leak_checks"]}
+webrender_api = {path = "../webrender_api", features=["serialize","deserialize"]}