Break crashpad_handler into lib and exe for Windows

handler/handler.gyp

Index: handler/handler.gyp
diff --git a/handler/handler.gyp b/handler/handler.gyp
index 20df3d7388942cf5165ac55cfafa2724fc48efc8..e7f54c82dd776aa643f489d14af5af987353abe7 100644
--- a/handler/handler.gyp
+++ b/handler/handler.gyp
@@ -19,8 +19,10 @@
   ],
   'targets': [
     {
-      'target_name': 'crashpad_handler',
-      'type': 'executable',
+      # This target exists so that the crashpad_handler can be embedded into
+      # another binary.
+      'target_name': 'crashpad_handler_lib',
+      'type': 'static_library',
       'dependencies': [
         '../client/client.gyp:crashpad_client',
         '../compat/compat.gyp:crashpad_compat',
@@ -40,10 +42,26 @@
         'mac/crash_report_exception_handler.h',
         'mac/exception_handler_server.cc',
         'mac/exception_handler_server.h',
-        'main.cc',
+        'handler_main.cc',
+        'handler_main.h',
         'win/crash_report_exception_handler.cc',
         'win/crash_report_exception_handler.h',
       ],
+    },
+    {
+      'target_name': 'crashpad_handler',
+      'type': 'executable',
+      'dependencies': [
+        '../third_party/mini_chromium/mini_chromium.gyp:base',
+        '../tools/tools.gyp:crashpad_tool_support',
+        'crashpad_handler_lib',
+      ],
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        'main.cc',
+      ],
 
       'conditions': [
         ['OS=="mac"', {