Make delegate_execute GetLaunchMode() check for default browser.

win8/delegate_execute/command_execute_impl.cc

Index: win8/delegate_execute/command_execute_impl.cc
diff --git a/win8/delegate_execute/command_execute_impl.cc b/win8/delegate_execute/command_execute_impl.cc
index 0d05dc517ee251e2d2eb8eb5cd3aed2d98847394..325d7d4bf84cb83a5502d5e69885f872502e5f7c 100644
--- a/win8/delegate_execute/command_execute_impl.cc
+++ b/win8/delegate_execute/command_execute_impl.cc
@@ -133,11 +133,12 @@ bool CommandExecuteImpl::path_provider_initialized_ = false;
 //    the launch scheme (or url) and the activation verb.
 // 5- Windows calls CommandExecuteImpl::Getvalue()
 //    Here we need to return AHE_IMMERSIVE or AHE_DESKTOP. That depends on:
-//    a) if run in high-integrity return AHE_DESKTOP
+//    a) if run in high-integrity return AHE_DESKTOP.
 //    b) else we return what GetLaunchMode() tells us, which is:
-//       i) if the command line --force-xxx is present return that
-//       ii) if the registry 'launch_mode' exists return that
-//       iii) else return AHE_DESKTOP
+//       i) if chrome is not the default browser, return AHE_DESKTOP
+//       ii) if the command line --force-xxx is present return that
+//       iii) if the registry 'launch_mode' exists return that
+//       iv) else return AHE_DESKTOP
 // 6- If we returned AHE_IMMERSIVE in step 5 windows might not call us back
 //    and simply activate chrome in metro by itself, however in some cases
 //    it might proceed at step 7.
@@ -209,6 +210,12 @@ STDMETHODIMP CommandExecuteImpl::GetValue(enum AHE_TYPE* pahe) {
   EC_HOST_UI_MODE mode = GetLaunchMode();
   *pahe = (mode == ECHUIM_DESKTOP) ? AHE_DESKTOP : AHE_IMMERSIVE;
 
+  // If we're going to return AHE_IMMERSIVE, then both the browser process and
+  // the metro viewer need to launch and connect before the user can start
+  // browsing.  However we must not launch the metro viewer until we get a
+  // call to CommandExecuteImpl::Execute().  If we wait until then to launch
+  // the browser process as well, it will appear laggy while they connect to
+  // each other, so we pre-launch the browser process now.
   if (*pahe == AHE_IMMERSIVE && verb_ != win8::kMetroViewerConnectVerb)
     LaunchChromeBrowserProcess();
   return S_OK;
@@ -415,6 +422,17 @@ EC_HOST_UI_MODE CommandExecuteImpl::GetLaunchMode() {
     launch_mode_determined = true;
     return launch_mode;
   }
+
+  base::FilePath chrome_exe;
+  if (!FindChromeExe(&chrome_exe) ||
+      ShellUtil::GetChromeDefaultStateFromPath(chrome_exe) !=
+          ShellUtil::DefaultState::IS_DEFAULT) {
+    AtlTrace("Chrome is not default: launching in desktop mode\n");
+    launch_mode = ECHUIM_DESKTOP;
+    launch_mode_determined = true;
+    return launch_mode;
+  }
+
   if (GetAsyncKeyState(VK_SHIFT) && GetAsyncKeyState(VK_F11)) {
     AtlTrace("Hotkey: launching in immersive mode\n");
     launch_mode = ECHUIM_IMMERSIVE;