[chromecast] Add concrete implementation for CastURLLoaderThrottle.

Bug: b/120907590
Merge-With: eureka-internal/260345
Test: Manual test on device
Change-Id: I5c2063815cbeae78761496871db1bf2e804c82a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1554901
Reviewed-by: Zhongyi Shi <zhongyi@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Junbo Ke <juke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#649637}

diff --git a/chromecast/common/DEPS b/chromecast/common/DEPS
index edb3a20..cd2c7fb 100644
--- a/chromecast/common/DEPS
+++ b/chromecast/common/DEPS

@@ -7,8 +7,9 @@
   "+extensions/shell/common/api",
   "+extensions/shell/grit",
   "+mojo/public/cpp/bindings",
-  "+services/service_manager/public/cpp",
+  "+net/http",
   "+services/network/public/cpp",
+  "+services/service_manager/public/cpp",
   "+ui/accessibility",
   "+ui/base",
   "+ui/gfx",