Starts the mojoification of AppCache.

First, convert all enums and structs used by existing IPCs to mojo

Next CL will define the Host and Renderer interfaces.

Bug: 611938
Change-Id: I689b7399ad903197073ca15763d73d5bfff3207f
Reviewed-on: https://chromium-review.googlesource.com/790174
Reviewed-by: Ken Buchanan <[email protected]>
Reviewed-by: Nick Carter <[email protected]>
Reviewed-by: Joshua Bell <[email protected]>
Commit-Queue: Nicholas Verne <[email protected]>
Cr-Commit-Position: refs/heads/master@{#520772}
diff --git a/content/common/BUILD.gn b/content/common/BUILD.gn
index 7ab38b9..8f53cb4 100644
--- a/content/common/BUILD.gn
+++ b/content/common/BUILD.gn
@@ -561,6 +561,7 @@
   cpp_only = true
 
   sources = [
+    "appcache.mojom",
     "associated_interfaces.mojom",
     "child.mojom",
     "child_control.mojom",