Move GetWebstoreLaunchURL and GetWebstoreItemDetailURLPrefix to extensions/common/extension_urls.h.

extensions/common/extension_urls.cc

Index: extensions/common/extension_urls.cc
diff --git a/extensions/common/extension_urls.cc b/extensions/common/extension_urls.cc
index ba72a63ef21971225eb3a4d124d569a57e223a9f..75a1bec1f52ab949b3a8278efe591832d6d8725f 100644
--- a/extensions/common/extension_urls.cc
+++ b/extensions/common/extension_urls.cc
@@ -4,11 +4,21 @@
 
 #include "extensions/common/extension_urls.h"
 
+#include "base/command_line.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "extensions/common/constants.h"
+#include "extensions/common/switches.h"
 #include "url/gurl.h"
 
+namespace {
+
+// The greatest common prefixes of the main extensions gallery's browse and
+// download URLs.
+const char kGalleryBrowsePrefix[] = "https://chrome.google.com/webstore";
+
+}  // namespace
+
 namespace extensions {
 
 const char kEventBindings[] = "event_bindings";
@@ -22,4 +32,19 @@ bool IsSourceFromAnExtension(const base::string16& source) {
                     true /* case-sensitive */);
 }
 
+std::string GetWebstoreLaunchURL() {
+  std::string gallery_prefix = kGalleryBrowsePrefix;
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAppsGalleryURL)) {
+    gallery_prefix = CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+        switches::kAppsGalleryURL);
+    if (EndsWith(gallery_prefix, "/", true))
+      gallery_prefix = gallery_prefix.substr(0, gallery_prefix.length() - 1);
+  }
+  return gallery_prefix;
+}
+
+std::string GetWebstoreItemDetailURLPrefix() {
+  return GetWebstoreLaunchURL() + "/detail/";
+}
+
 }  // namespace extensions