Restore --url-mappings switch for Mojo apptests.

Revert a portion of https://codereview.chromium.org/1057603003
This is needed to mock out dependencies for apptests.
(blocking view_manager_apptests from passing)

We are unable to specify mappings in code for now.
(would need a Shell interface function or similar)

TODO: Add a minimal test of --url-mappings behavior.

BUG=NONE
TEST=mojo_shell respects the --url-mappings switch.
R=jam@chromium.org
TBR=sky@chromium.org

Review URL: https://codereview.chromium.org/1099923003

Cr-Commit-Position: refs/heads/master@{#326198}

4 files changed, 51 insertions, 0 deletions

diff --git a/mojo/shell/application_manager/application_manager_unittest.cc b/mojo/shell/application_manager/application_manager_unittest.cc
index cc420a7..f801e36 100644
--- a/mojo/shell/application_manager/application_manager_unittest.cc
+++ b/mojo/shell/application_manager/application_manager_unittest.cc
@@ -487,6 +487,33 @@ TEST_F(ApplicationManagerTest, NoArgs) {
   EXPECT_EQ(0U, app_args.size());
 }
 
+// Confirm that url mappings are respected.
+TEST_F(ApplicationManagerTest, URLMapping) {
+  ApplicationManager am(&test_delegate_);
+  GURL test_url("test:test");
+  GURL test_url2("test:test2");
+  test_delegate_.AddMapping(test_url, test_url2);
+  TestApplicationLoader* loader = new TestApplicationLoader;
+  loader->set_context(&context_);
+  am.SetLoaderForURL(scoped_ptr<ApplicationLoader>(loader), test_url2);
+  {
+    // Connext to the mapped url
+    TestServicePtr test_service;
+    am.ConnectToService(test_url, &test_service);
+    TestClient test_client(test_service.Pass());
+    test_client.Test("test");
+    loop_.Run();
+  }
+  {
+    // Connext to the target url
+    TestServicePtr test_service;
+    am.ConnectToService(test_url2, &test_service);
+    TestClient test_client(test_service.Pass());
+    test_client.Test("test");
+    loop_.Run();
+  }
+}
+
 TEST_F(ApplicationManagerTest, ClientError) {
   test_client_->Test("test");
   EXPECT_TRUE(HasFactoryForTestURL());
diff --git a/mojo/shell/context.cc b/mojo/shell/context.cc
index fc56476..0cc27d1 100644
--- a/mojo/shell/context.cc
+++ b/mojo/shell/context.cc
@@ -84,6 +84,23 @@ bool ConfigureURLMappings(const base::CommandLine& command_line,
     resolver->AddOriginMapping(GURL(origin_mapping.origin),
                                GURL(origin_mapping.base_url));
 
+  if (command_line.HasSwitch(switches::kURLMappings)) {
+    const std::string mappings =
+        command_line.GetSwitchValueASCII(switches::kURLMappings);
+
+    base::StringPairs pairs;
+    if (!base::SplitStringIntoKeyValuePairs(mappings, '=', ',', &pairs))
+      return false;
+    using StringPair = std::pair<std::string, std::string>;
+    for (const StringPair& pair : pairs) {
+      const GURL from(pair.first);
+      const GURL to = context->ResolveCommandLineURL(pair.second);
+      if (!from.is_valid() || !to.is_valid())
+        return false;
+      resolver->AddURLMapping(from, to);
+    }
+  }
+
   return true;
 }
 
diff --git a/mojo/shell/switches.cc b/mojo/shell/switches.cc
index 28e7d05..1fff40d 100644
--- a/mojo/shell/switches.cc
+++ b/mojo/shell/switches.cc
@@ -55,4 +55,10 @@ const char kPredictableAppFilenames[] = "predictable-app-filenames";
 // seconds or when the shell exits.
 const char kTraceStartup[] = "trace-startup";
 
+// Specifies a set of mappings to apply when resolving urls. The value is a set
+// of ',' separated mappings, where each mapping consists of a pair of urls
+// giving the to/from url to map. For example, 'a=b,c=d' contains two mappings,
+// the first maps 'a' to 'b' and the second 'c' to 'd'.
+const char kURLMappings[] = "url-mappings";
+
 }  // namespace switches
diff --git a/mojo/shell/switches.h b/mojo/shell/switches.h
index ff2eb6c..31cac8f 100644
--- a/mojo/shell/switches.h
+++ b/mojo/shell/switches.h
@@ -23,6 +23,7 @@ extern const char kMapOrigin[];
 extern const char kOrigin[];
 extern const char kPredictableAppFilenames[];
 extern const char kTraceStartup[];
+extern const char kURLMappings[];
 
 }  // namespace switches