export blink::Platform symbols in shared_library builds

third_party/WebKit/public/platform/WebCommon.h

Index: third_party/WebKit/public/platform/WebCommon.h
diff --git a/third_party/WebKit/public/platform/WebCommon.h b/third_party/WebKit/public/platform/WebCommon.h
index 9d0a40af61826fe6ff035cb73b18b9cb2893a29f..66f7e50939b23a5ad6b9caa6b2a14e99e5f7a9ac 100644
--- a/third_party/WebKit/public/platform/WebCommon.h
+++ b/third_party/WebKit/public/platform/WebCommon.h
@@ -60,14 +60,20 @@
         #else // BLINK_COMMON_IMPLEMENTATION
             #define BLINK_COMMON_EXPORT __declspec(dllimport)
         #endif
+        #define BLINK_PLATFORM_HIDDEN

[dcheng, 2016/03/07 04:42:08]

I wouldn't change these macros.

[Mostyn Bramley-Moore, 2016/03/07 06:38:31]

OK.  BTW, the presubmit hooks complain that macros should not be indented-
should I fix that here, or will that be taken care of in a clang-format run
later?

+        #define BLINK_PLATFORM_EXPORT_CLASS
     #else // defined(WIN32)
+        #define BLINK_PLATFORM_HIDDEN __attribute__((visibility("hidden")))
         #define BLINK_EXPORT __attribute__((visibility("default")))
-        #define BLINK_PLATFORM_EXPORT __attribute__((visibility("default")))
-        #define BLINK_COMMON_EXPORT __attribute__((visibility("default")))
+        #define BLINK_PLATFORM_EXPORT BLINK_EXPORT
+        #define BLINK_PLATFORM_EXPORT_CLASS BLINK_EXPORT
+        #define BLINK_COMMON_EXPORT BLINK_EXPORT
     #endif
 #else // defined(COMPONENT_BUILD)
     #define BLINK_EXPORT
     #define BLINK_PLATFORM_EXPORT
+    #define BLINK_PLATFORM_EXPORT_CLASS
+    #define BLINK_PLATFORM_HIDDEN
     #define BLINK_COMMON_EXPORT
 #endif