AppCache: Move browser-only constant from content/common/.

The file name of the AppCache SQLite database is an implementation
detail that is only relevant to the browser process. The renderer should
not be able to access the database directly.

The CL also clarifies the code declaring a few related AppCache
constants. Most importantly, the AppCache code used to implement a
content::kMB global variable, which is now in an anonymous namespace in
the only file that needs it.

Change-Id: I7c66543ded40c241622b0587e2abce1de15b18f5
Reviewed-on: https://chromium-review.googlesource.com/1189345
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Joshua Bell <jsbell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586333}

content/browser/appcache/appcache_storage_impl.cc

@@ -44,17 +44,20 @@
 
 namespace content {
 
-const int kMB = 1024 * 1024;
+namespace {
+
+constexpr const int kMB = 1024 * 1024;
 
 // Hard coded default when not using quota management.
-static const int kDefaultQuota = 5 * kMB;
+constexpr const int kDefaultQuota = 5 * kMB;
 
-static const int kMaxAppCacheDiskCacheSize = 250 * kMB;
-static const int kMaxAppCacheMemDiskCacheSize = 10 * kMB;
-static const base::FilePath::CharType kDiskCacheDirectoryName[] =
-    FILE_PATH_LITERAL("Cache");
+constexpr const int kMaxAppCacheDiskCacheSize = 250 * kMB;
+constexpr const int kMaxAppCacheMemDiskCacheSize = 10 * kMB;
 
-namespace {
+constexpr base::FilePath::CharType kDiskCacheDirectoryName[] =
+    FILE_PATH_LITERAL("Cache");
+constexpr base::FilePath::CharType kAppCacheDatabaseName[] =
+    FILE_PATH_LITERAL("Index");
 
 // Helpers for clearing data from the AppCacheDatabase.
 bool DeleteGroupAndRelatedRecords(

content/common/appcache_interfaces.cc

@@ -17,9 +17,6 @@ namespace content {
 const char kHttpGETMethod[] = "GET";
 const char kHttpHEADMethod[] = "HEAD";
 
-const base::FilePath::CharType kAppCacheDatabaseName[] =
-    FILE_PATH_LITERAL("Index");
-
 AppCacheNamespace::AppCacheNamespace()
     : type(APPCACHE_FALLBACK_NAMESPACE), is_pattern(false) {}
 

content/common/appcache_interfaces.h

@@ -117,9 +117,6 @@ CONTENT_EXPORT bool IsSchemeSupportedForAppCache(const GURL& url);
 CONTENT_EXPORT bool IsMethodSupportedForAppCache(
     const std::string& method);
 
-CONTENT_EXPORT extern const base::FilePath::CharType
-    kAppCacheDatabaseName[];
-
 }  // namespace
 
 #endif  // CONTENT_COMMON_APPCACHE_INTERFACES_H_