media: Set RUNPATH in cdm adapter in GN component build

media/cdm/ppapi/ppapi_cdm_adapter.gni

Index: media/cdm/ppapi/ppapi_cdm_adapter.gni
diff --git a/media/cdm/ppapi/ppapi_cdm_adapter.gni b/media/cdm/ppapi/ppapi_cdm_adapter.gni
index a8e80ec64616c52b849e74072ae75473fa332faa..c4c7f878e4cffe406b98997a35cb466013c606ef 100644
--- a/media/cdm/ppapi/ppapi_cdm_adapter.gni
+++ b/media/cdm/ppapi/ppapi_cdm_adapter.gni
@@ -59,8 +59,8 @@ template("ppapi_cdm_adapter") {
       libs += [ "rt" ]
     }
 
-    if (is_linux && !is_component_build) {
-      # CDM adapter depends on a CDM even in non-component builds.
+    if (is_linux) {
+      # CDM adapter depends on a CDM in component and non-component builds.
       configs += [ "//build/config/gcc:rpath_for_built_shared_libraries" ]

[ddorwin, 2016/05/16 18:11:12]

I know we need to set rpath for the adapter, but two things:
1. The warning not to use this for release builds:
https://code.google.com/p/chromium/codesearch#chromium/src/build/config/gcc/B...
2. It seems this isn't intended to do what we want (bind to the same directory).
If shlib_subdir was set, I don't think this would do what we want.

[xhwang, 2016/05/16 18:23:07]

This was discussed when we added this back. See
https://bugs.chromium.org/p/chromium/issues/detail?id=583009#c18
Good point. Maybe we should just manually set rpath here? I don't know what's
the plan to use a separate shlib_subdir for GN. At some point when we deprecate
cdm adapters this problem will go away.

[ddorwin, 2016/05/16 18:28:46]

thestig@: Should we update the documentation in the source link above?
If possible, that would be best. If not, then we'll just have to live with it
until then.

[Lei Zhang, 2016/05/17 20:31:15]

Meh. The config("executable_ldconfig") section in build/config/gcc/BUILD.gn
normally already takes caer of the component build case. ppapi_cdm_adapter is
probably one of the few exceptions.

     }