Allow chrome to become the os default handler for arbitrary protocols on mac/win.

chrome/browser/shell_integration_mac.mm

Index: chrome/browser/shell_integration_mac.mm
diff --git a/chrome/browser/shell_integration_mac.mm b/chrome/browser/shell_integration_mac.mm
index 7bf1dcb3fcdedd489248398b9d703fe6027b2ebc..1750ad83cf1e8a22755bad0b60076db3653820aa 100644
--- a/chrome/browser/shell_integration_mac.mm
+++ b/chrome/browser/shell_integration_mac.mm
@@ -5,11 +5,13 @@
 #include "chrome/browser/shell_integration.h"
 
 #include "base/mac/mac_util.h"
+#include "base/mac/foundation_util.h"
 #include "chrome/browser/platform_util.h"
 #import "third_party/mozilla/NSWorkspace+Utils.h"
 
-// Sets Chromium as default browser (only for current user). Returns false if
-// this operation fails.
+// Sets Chromium as default browser to be used by the operating system. This
+// applies only for the current user. Returns false if this cannot be done, or
+// if the operation fails.
 bool ShellIntegration::SetAsDefaultBrowser() {
   if (!platform_util::CanSetAsDefaultBrowser())
     return false;
@@ -17,22 +19,67 @@ bool ShellIntegration::SetAsDefaultBrowser() {
   // We really do want the main bundle here, not base::mac::MainAppBundle(),
   // which is the bundle for the framework.
   NSString* identifier = [[NSBundle mainBundle] bundleIdentifier];
+  if (!identifier)
+    return false;
+
   [[NSWorkspace sharedWorkspace] setDefaultBrowserWithIdentifier:identifier];
   return true;
 }
 
+// Sets Chromium as the default application to be used by the operating system
+// for the given protocol. This applies only for the current user. Returns false
+// if this cannot be done, or if the operation fails.
+bool ShellIntegration::SetAsDefaultProtocolClient(const std::string& protocol) {
+  if (protocol.empty())
+    return false;
+
+  if (!platform_util::CanSetAsDefaultProtocolClient(protocol))
+    return false;
+
+  // We really do want the main bundle here, not base::mac::MainAppBundle(),
+  // which is the bundle for the framework.
+  NSString* identifier = [[NSBundle mainBundle] bundleIdentifier];
+  if (!identifier)
+    return false;
+
+  NSString* protocol_ns = [NSString stringWithUTF8String:protocol.c_str()];
+  OSStatus return_code =
+      LSSetDefaultHandlerForURLScheme(base::mac::NSToCFCast(protocol_ns),
+                                      base::mac::NSToCFCast(identifier));
+  return return_code == noErr;
+}
+
 namespace {
 
 // Returns true if |identifier| is the bundle id of the default browser.
 bool IsIdentifierDefaultBrowser(NSString* identifier) {
-  NSString* defaultBrowser =
+  NSString* default_browser =
       [[NSWorkspace sharedWorkspace] defaultBrowserIdentifier];
-  if (!defaultBrowser)
+  if (!default_browser)
     return false;
+
   // We need to ensure we do the comparison case-insensitive as LS doesn't
   // persist the case of our bundle id.
   NSComparisonResult result =
-    [defaultBrowser caseInsensitiveCompare:identifier];
+      [default_browser caseInsensitiveCompare:identifier];
+  return result == NSOrderedSame;
+}
+
+// Returns true if |identifier| is the bundle id of the default client
+// application for the given protocol.
+bool IsIdentifierDefaultProtocolClient(NSString* identifier,
+                                       NSString* protocol) {
+  CFStringRef default_client_cf =
+      LSCopyDefaultHandlerForURLScheme(base::mac::NSToCFCast(protocol));
+  NSString* default_client = static_cast<NSString*>(
+      base::mac::CFTypeRefToNSObjectAutorelease(default_client_cf));
+  if (!default_client)
+    return false;
+
+  // We need to ensure we do the comparison case-insensitive as LS doesn't
+  // persist the case of our bundle id.
+  NSComparisonResult result =
+      [default_client caseInsensitiveCompare:identifier];
   return result == NSOrderedSame;
 }
 
@@ -42,16 +89,36 @@ bool IsIdentifierDefaultBrowser(NSString* identifier) {
 // return the appropriate state. (Defined as being the handler for HTTP/HTTPS
 // protocols; we don't want to report "no" here if the user has simply chosen
 // to open HTML files in a text editor and FTP links with an FTP client.)
-ShellIntegration::DefaultBrowserState ShellIntegration::IsDefaultBrowser() {
-  // As above, we want to use the real main bundle.
-  NSString* myIdentifier = [[NSBundle mainBundle] bundleIdentifier];
-  if (!myIdentifier)
-    return UNKNOWN_DEFAULT_BROWSER;
-  return IsIdentifierDefaultBrowser(myIdentifier) ? IS_DEFAULT_BROWSER
-                                                  : NOT_DEFAULT_BROWSER;
+ShellIntegration::DefaultWebClientState ShellIntegration::IsDefaultBrowser() {
+  // We really do want the main bundle here, not base::mac::MainAppBundle(),
+  // which is the bundle for the framework.
+  NSString* my_identifier = [[NSBundle mainBundle] bundleIdentifier];
+  if (!my_identifier)
+    return UNKNOWN_DEFAULT_WEB_CLIENT;
+
+  return IsIdentifierDefaultBrowser(my_identifier) ? IS_DEFAULT_WEB_CLIENT
+                                                   : NOT_DEFAULT_WEB_CLIENT;
 }
 
 // Returns true if Firefox is the default browser for the current user.
 bool ShellIntegration::IsFirefoxDefaultBrowser() {
   return IsIdentifierDefaultBrowser(@"org.mozilla.firefox");
 }
+
+// Attempt to determine if this instance of Chrome is the default client
+// application for the given protocol and return the appropriate state.
+ShellIntegration::DefaultWebClientState
+    ShellIntegration::IsDefaultProtocolClient(const std::string& protocol) {
+  if (protocol.empty())
+    return UNKNOWN_DEFAULT_WEB_CLIENT;
+
+  // We really do want the main bundle here, not base::mac::MainAppBundle(),
+  // which is the bundle for the framework.
+  NSString* my_identifier = [[NSBundle mainBundle] bundleIdentifier];
+  if (!my_identifier)
+    return UNKNOWN_DEFAULT_WEB_CLIENT;
+
+  NSString* protocol_ns = [NSString stringWithUTF8String:protocol.c_str()];
+  return IsIdentifierDefaultProtocolClient(my_identifier, protocol_ns) ?
+      IS_DEFAULT_WEB_CLIENT : NOT_DEFAULT_WEB_CLIENT;
+}