Export content_common dependency from some content targets.

Many Blink headers in public/platform/ include other headers in same directory
with relative paths. For now they have |#include "WebFoo.h"|, and we'd like to
change it to |#include "public/platform/WebFoo.h"|. This CL is necessary to
specify correct include path for them.

BUG=

Review URL: https://codereview.chromium.org/410743007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285131 0039d316-1c4b-4281-b951-d872f2087c98

content/content.gyp

@@ -46,6 +46,9 @@
             'content_browser',
             'content_common',
           ],
+          'export_dependent_settings': [
+            'content_common',
+          ],
           'conditions': [
             ['OS != "ios"', {
               'dependencies': [
@@ -70,6 +73,9 @@
           'dependencies': [
             'content_common',
           ],
+          'export_dependent_settings': [
+            'content_common',
+          ],
           'conditions': [
             ['chrome_multiple_dll', {
               'defines': [
@@ -88,6 +94,9 @@
           'dependencies': [
             'content_common',
           ],
+          'export_dependent_settings': [
+            'content_common',
+          ],
           'conditions': [
             ['chrome_multiple_dll', {
               'defines': [
@@ -121,6 +130,9 @@
             'content_common',
             'content_resources.gyp:content_resources',
           ],
+          'export_dependent_settings': [
+            'content_common',
+          ],
           'conditions': [
             ['java_bridge==1', {
               'dependencies': [