handler/mac: Support the in-Chromium component=shared_library

configuration.

When depending on shared libraries such as libbase.dylib,
crashpad_handler must have an LC_RPATH pointing to the
out/{Debug,Release} directory relative to its home deep within
Chromium.app.

BUG=chromium:466964
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/1009633002

handler/handler.gyp

@@ -15,6 +15,7 @@
 {
   'includes': [
     '../build/crashpad.gypi',
+    '../build/crashpad_in_chromium.gypi',
   ],
   'conditions': [
     ['OS=="mac"', {
@@ -43,6 +44,28 @@
             'mac/exception_handler_server.h',
             'mac/main.cc',
           ],
+
+	  # In an in-Chromium build with component=shared_library,
+	  # crashpad_handler will depend on shared libraries such as
+	  # libbase.dylib located in out/{Debug,Release} via the @rpath
+	  # mechanism. When crashpad_handler is copied to its home deep inside
+	  # the Chromium app bundle, it needs to have an LC_RPATH command
+	  # pointing back to the directory containing these dependency
+	  # libraries.
+          'variables': {
+            'component%': 'static_library',
+          },
+          'conditions': [
+            ['crashpad_in_chromium!=0 and component=="shared_library"', {
+              'xcode_settings': {
+                'LD_RUNPATH_SEARCH_PATHS': [  # -Wl,-rpath
+                  # Get back from
+                  # Chromium.app/Contents/Versions/V/Framework.framework/Helpers
+                  '@loader_path/../../../../../..',
+                ],
+              },
+            }],
+          ],
         },
       ],
     }, {