Enable HTTP loading in Mojo dart content handler

services/dart/dart_app.cc

Index: services/dart/dart_app.cc
diff --git a/services/dart/dart_app.cc b/services/dart/dart_app.cc
index cf13608aa6107761a2d9c46a4c9d53cb80622c2d..600a61c0012d0f87a854c323f3fff7865cdd2966 100644
--- a/services/dart/dart_app.cc
+++ b/services/dart/dart_app.cc
@@ -15,6 +15,7 @@
 #include "mojo/dart/embedder/dart_state.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 #include "third_party/zlib/google/zip_reader.h"
+#include "url/gurl.h"
 
 using mojo::Application;
 
@@ -38,6 +39,59 @@ DartApp::DartApp(mojo::InterfaceRequest<Application> application_request,
       base::Bind(&DartApp::OnAppLoaded, base::Unretained(this)));
 }
 
+// Assume that |url| ends in a file name, and as a peer to the filename
+// is the packages directory.
+// 1) Strip the filename.
+// 2) Append with packages/.
+// 3) Reconstruct full url.
+static std::string SimplePackageRootFromUrl(std::string url) {
+  GURL gurl = GURL(url);
+  base::FilePath path = base::FilePath(gurl.path());
+  path = path.DirName();
+  path = path.Append("packages");
+  path = path.AsEndingWithSeparator();
+  const std::string& path_string = path.value();
+  GURL::Replacements path_replacement;
+  path_replacement.SetPath(path_string.data(),
+                           url::Component(0, path_string.size()));
+  gurl = gurl.ReplaceComponents(path_replacement);
+  return gurl.spec();
+}
+
+// Returns the path component from |url|.
+static std::string ExtractPath(std::string url) {
+  GURL gurl = GURL(url);
+  return gurl.path();
+}
+
+static bool IsFileScheme(std::string url) {
+  GURL gurl = GURL(url);
+  return gurl.SchemeIsFile();
+}
+
+DartApp::DartApp(mojo::InterfaceRequest<Application> application_request,
+                 const std::string& url,
+                 bool strict)
+    : application_request_(application_request.Pass()) {
+  config_.application_data = reinterpret_cast<void*>(this);
+  config_.strict_compilation = strict;
+  if (IsFileScheme(url)) {
+    // Strip file:// and use the path directly.
+    config_.script_uri = ExtractPath(url);
+    config_.package_root = ExtractPath(SimplePackageRootFromUrl(url));
+    config_.use_network_loader = false;
+  } else {
+    // Use the full url.
+    config_.script_uri = url;
+    config_.package_root = SimplePackageRootFromUrl(url);
+    config_.use_network_loader = true;
+  }
+  config_.SetVmFlags(nullptr, 0);
+
+  base::MessageLoop::current()->PostTask(FROM_HERE,
+      base::Bind(&DartApp::OnAppLoaded, base::Unretained(this)));
+}
+
 DartApp::~DartApp() {
 }