Use HTTPS links for Google domains in docs

Since almost all Google domains support HTTPS, and it is a good practice to
use HTTPS wherever possible, thus in this patch, I changed most HTTP links
to https whose domains are known to support HTTPS well.

Modifications are generated by running these commands in src/docs directory:
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/www.chromium.org/https:\/\/ptop.only.wip.la:443\/https\/www.chromium.org/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/developer.android.com/https:\/\/ptop.only.wip.la:443\/https\/developer.android.com/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/dev.chromium.org/https:\/\/ptop.only.wip.la:443\/https\/dev.chromium.org/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/build.chromium.org/https:\/\/ptop.only.wip.la:443\/https\/build.chromium.org/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/src.chromium.org/https:\/\/ptop.only.wip.la:443\/https\/src.chromium.org/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/crbug.com/https:\/\/ptop.only.wip.la:443\/https\/crbug.com/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/groups.google.com/https:\/\/ptop.only.wip.la:443\/https\/groups.google.com/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/cs.chromium.org/https:\/\/ptop.only.wip.la:443\/https\/cs.chromium.org/g' *.md
sed -i 's/https:\/\/ptop.only.wip.la:443\/http\/codereview.chromium.org/https:\/\/ptop.only.wip.la:443\/https\/codereview.chromium.org/g' *.md

BUG=

Review-Url: https://codereview.chromium.org/2545363002
Cr-Commit-Position: refs/heads/master@{#436501}
diff --git a/docs/linux_plugins.md b/docs/linux_plugins.md
index 24eefd9..6c1eae60 100644
--- a/docs/linux_plugins.md
+++ b/docs/linux_plugins.md
@@ -14,7 +14,7 @@
 
 ### Chromium-specific
 
-*   [Chromium's plugin architecture](http://dev.chromium.org/developers/design-documents/plugin-architecture)
+*   [Chromium's plugin architecture](https://dev.chromium.org/developers/design-documents/plugin-architecture)
     -- may be out of date but will be worth reading
 
 ## Code to reference