Wire in the device observatory port while initializing the Dart VM

sky/engine/core/script/dart_init.cc

@@ -136,9 +136,10 @@ Dart_Isolate IsolateCreateCallback(const char* script_uri,
       DartJni::InitForIsolate();
 #endif
       DartRuntimeHooks::Install(DartRuntimeHooks::DartIOIsolate);
-      if (SkySettings::Get().enable_observatory) {
+      const SkySettings& settings = SkySettings::Get();
+      if (settings.enable_observatory) {
         std::string ip = "127.0.0.1";
-        const intptr_t port = 8181;
+        const intptr_t port = settings.observatory_port;
         const bool service_isolate_booted = DartServiceIsolate::Startup(
             ip, port, DartLibraryTagHandler, IsRunningPrecompiledCode(), error);
         CHECK(service_isolate_booted) << error;

sky/engine/public/platform/sky_settings.h

@@ -5,10 +5,13 @@
 #ifndef SKY_ENGINE_PUBLIC_PLATFORM_SKY_SETTINGS_H_
 #define SKY_ENGINE_PUBLIC_PLATFORM_SKY_SETTINGS_H_
 
+#include <stdint.h>
+
 namespace blink {
 
 struct SkySettings {
   bool enable_observatory = false;
+  uint32_t observatory_port = 8181;
   bool start_paused = false;
   bool enable_dart_checked_mode = false;
 
@@ -16,6 +19,6 @@ struct SkySettings {
   static void Set(const SkySettings& settings);
 };
 
-} // namespace blink
+}  // namespace blink
 
 #endif  // SKY_ENGINE_PUBLIC_PLATFORM_SKY_SETTINGS_H_

sky/shell/shell.cc

@@ -5,6 +5,7 @@
 #include "sky/shell/shell.h"
 
 #include <memory>
+#include <sstream>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ -81,9 +82,22 @@ void Shell::InitStandalone() {
   base::CommandLine& command_line = *base::CommandLine::ForCurrentProcess();
 
   blink::SkySettings settings;
+  // Enable Observatory
   settings.enable_observatory =
       !command_line.HasSwitch(switches::kNonInteractive);
+  // Set Observatory Port
+  if (command_line.HasSwitch(switches::kDeviceObservatoryPort)) {
+    auto port_string =
+        command_line.GetSwitchValueASCII(switches::kDeviceObservatoryPort);
+    std::stringstream stream(port_string);
+    uint32_t port = 0;
+    if (stream >> port) {
+      settings.observatory_port = port;
+    }
+  }
+  // Start Paused
   settings.start_paused = command_line.HasSwitch(switches::kStartPaused);
+  // Set Checked Mode
   settings.enable_dart_checked_mode =
       command_line.HasSwitch(switches::kEnableCheckedMode);
   blink::SkySettings::Set(settings);

sky/shell/switches.cc

@@ -17,6 +17,7 @@ const char kNonInteractive[] = "non-interactive";
 const char kPackageRoot[] = "package-root";
 const char kStartPaused[] = "start-paused";
 const char kTraceStartup[] = "trace-startup";
+const char kDeviceObservatoryPort[] = "observatory-port";
 
 void PrintUsage(const std::string& executable_name) {
   std::cerr << "Usage: " << executable_name
@@ -26,6 +27,7 @@ void PrintUsage(const std::string& executable_name) {
             << " --" << kTraceStartup
             << " --" << kFLX << "=FLX"
             << " --" << kPackageRoot << "=PACKAGE_ROOT"
+            << " --" << kDeviceObservatoryPort << "=8181"
             << " [ MAIN_DART ]" << std::endl;
 }
 

sky/shell/switches.h

@@ -18,6 +18,7 @@ extern const char kNonInteractive[];
 extern const char kPackageRoot[];
 extern const char kStartPaused[];
 extern const char kTraceStartup[];
+extern const char kDeviceObservatoryPort[];
 
 void PrintUsage(const std::string& executable_name);