servo: Merge #16867 - Update offscreen_gl_context (from MortimerGoro:update_offscreen_gl_ctx); r=jdm

<!-- Please describe your changes on the following line: -->

Adds https://github.com/emilio/rust-offscreen-rendering-context/pull/97 and https://github.com/emilio/rust-offscreen-rendering-context/pull/98 required to run some WebGL demos

---
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- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [x] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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Source-Repo: https://github.com/servo/servo
Source-Revision: 00a5da36fbe8fdc8336ff1800ad16d0141c77c47

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : fe30e163752773708e2fd1f00abe0662237cff24

servo/Cargo.lock

@@ -311,7 +311,7 @@ dependencies = [
  "ipc-channel 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
- "offscreen_gl_context 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "offscreen_gl_context 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_config 0.0.1",
  "webrender_traits 0.39.0 (git+https://github.com/servo/webrender)",
 ]
@@ -473,7 +473,7 @@ dependencies = [
  "msg 0.0.1",
  "net 0.0.1",
  "net_traits 0.0.1",
- "offscreen_gl_context 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "offscreen_gl_context 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "serde 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1498,17 +1498,6 @@ name = "libc"
 version = "0.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "libloading"
-version = "0.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "target_build_utils 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "libloading"
 version = "0.4.0"
@@ -1903,7 +1892,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "offscreen_gl_context"
-version = "0.8.6"
+version = "0.8.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cgl 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1914,7 +1903,7 @@ dependencies = [
  "gleam 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "libloading 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libloading 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "osmesa-sys 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2356,7 +2345,7 @@ dependencies = [
  "msg 0.0.1",
  "net_traits 0.0.1",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
- "offscreen_gl_context 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "offscreen_gl_context 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "open 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2452,7 +2441,7 @@ dependencies = [
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
- "offscreen_gl_context 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "offscreen_gl_context 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "profile_traits 0.0.1",
  "rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3015,16 +3004,6 @@ dependencies = [
  "unicode-xid 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "target_build_utils"
-version = "0.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_codegen 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_json 0.9.10 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "task_info"
 version = "0.0.1"
@@ -3321,7 +3300,7 @@ dependencies = [
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
- "offscreen_gl_context 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "offscreen_gl_context 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "plane-split 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "thread_profiler 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3344,7 +3323,7 @@ dependencies = [
  "gleam 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "offscreen_gl_context 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "offscreen_gl_context 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3573,7 +3552,6 @@ dependencies = [
 "checksum leak 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "bd100e01f1154f2908dfa7d02219aeab25d0b9c7fa955164192e3245255a0c73"
 "checksum leaky-cow 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "40a8225d44241fd324a8af2806ba635fc7c8a7e9a7de4d5cf3ef54e71f5926fc"
 "checksum libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)" = "e7eb6b826bfc1fdea7935d46556250d1799b7fe2d9f7951071f4291710665e3e"
-"checksum libloading 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "fd1835a714c1f67ba073a493493c23686a480e2614e208c921834808b1f19d8f"
 "checksum libloading 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "be99f814beb3e9503a786a592c909692bb6d4fc5a695f6ed7987223acfbd5194"
 "checksum libz-sys 1.0.13 (registry+https://github.com/rust-lang/crates.io-index)" = "e5ee912a45d686d393d5ac87fac15ba0ba18daae14e8e7543c63ebf7fb7e970c"
 "checksum log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "880f77541efa6e5cc74e76910c9884d9859683118839d6a1dc3b11e63512565b"
@@ -3603,7 +3581,7 @@ dependencies = [
 "checksum num_cpus 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca313f1862c7ec3e0dfe8ace9fa91b1d9cb5c84ace3d00f5ec4216238e93c167"
 "checksum objc 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "877f30f37acef6749b1841cceab289707f211aecfc756553cd63976190e6cc2e"
 "checksum odds 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)" = "c3df9b730298cea3a1c3faa90b7e2f9df3a9c400d0936d6015e6165734eefcba"
-"checksum offscreen_gl_context 0.8.6 (registry+https://github.com/rust-lang/crates.io-index)" = "ce00d0caf8994f97a07be58dbd1c4d1e05904039d9ddb9286ca6ab144ea570b1"
+"checksum offscreen_gl_context 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)" = "3cadec7378139fd7e48badba0d59cbb6312c7e0eca9b5e3b8ec7a78fc0c6cb28"
 "checksum ogg 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "013b78ceb7fb82555a2f8a95d8e40866fe64a5d15b83c51b3e1fdd40cd903ed3"
 "checksum ogg_metadata 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb1753e64956b3afd900f788bf6d2e9d0986df39168be86f4b47ec2058d0c2f7"
 "checksum open 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3478ed1686bd1300c8a981a940abc92b06fac9cbef747f4c668d4e032ff7b842"
@@ -3679,7 +3657,6 @@ dependencies = [
 "checksum syntex_errors 0.58.1 (registry+https://github.com/rust-lang/crates.io-index)" = "867cc5c2d7140ae7eaad2ae9e8bf39cb18a67ca651b7834f88d46ca98faadb9c"
 "checksum syntex_pos 0.58.1 (registry+https://github.com/rust-lang/crates.io-index)" = "13ad4762fe52abc9f4008e85c4fb1b1fe3aa91ccb99ff4826a439c7c598e1047"
 "checksum syntex_syntax 0.58.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6e0e4dbae163dd98989464c23dd503161b338790640e11537686f2ef0f25c791"
-"checksum target_build_utils 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f42dc058080c19c6a58bdd1bf962904ee4f5ef1fe2a81b529f31dacc750c679f"
 "checksum tempdir 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "87974a6f5c1dfb344d733055601650059a3363de2a6104819293baff662132d6"
 "checksum tendril 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "4ce04c250d202db8004921e3d3bc95eaa4f2126c6937a428ae39d12d0e38df62"
 "checksum term 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "d168af3930b369cfe245132550579d47dfd873d69470755a19c2c6568dbbd989"