Replace web_cache_messages.h with Mojo service.

components/web_cache/browser/BUILD.gn

Index: components/web_cache/browser/BUILD.gn
diff --git a/components/web_cache/browser/BUILD.gn b/components/web_cache/browser/BUILD.gn
index 0afff18cafbf4a3910dd70d9a3ca65f8455f1bc0..e304cdb1c2cde9fba89f44f1fcadb4fdb1fdea32 100644
--- a/components/web_cache/browser/BUILD.gn
+++ b/components/web_cache/browser/BUILD.gn
@@ -13,8 +13,9 @@ source_set("browser") {
   deps = [
     "//base",
     "//components/prefs",
-    "//components/web_cache/common",
+    "//components/web_cache/public/interfaces",
     "//content/public/browser",
+    "//content/public/common",

[Sam McNally, 2016/03/10 22:59:34]

Should there be a corresponding addition to the gypi?

[leonhsl(Using Gerrit), 2016/03/11 02:56:24]

In components/web_cache.gypi, 'web_cache_browser' depends on --> 
'content/content.gyp:content_browser' depends on -->
'content/content.gyp:content_common', which  covers both //content/common and
//content/public/common. So no need to add deps again.

I think the root cause is that gyp has no separate targets for //content/common
and //content/public/common..

     "//third_party/WebKit/public:blink_headers",
   ]
 }