mac: Bump the deployment target to 10.11.

Bug: 1153883
Change-Id: I905596a4373b1381a1c882d65b83520d657b8246
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2565654Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833272}

build/config/mac/mac_sdk.gni

@@ -16,7 +16,7 @@ declare_args() {
   # additional code changes are required to be compliant with the availability
   # rules.
   # Must be of the form x.x.x for Info.plist files.
-  mac_deployment_target = "10.10.0"
+  mac_deployment_target = "10.11.0"
 
   # The value of the LSMinimmumSystemVersion in Info.plist files. This partially
   # controls the minimum supported version of macOS for Chromium by