Refactoring: Move some classes from content/child to platform

third_party/WebKit/public/platform/Platform.h

Index: third_party/WebKit/public/platform/Platform.h
diff --git a/third_party/WebKit/public/platform/Platform.h b/third_party/WebKit/public/platform/Platform.h
index a4b9fe7197665adc56bcd28af255c58fea89f871..7d17c59c85820194a37a869bcf9a2721c65a2512 100644
--- a/third_party/WebKit/public/platform/Platform.h
+++ b/third_party/WebKit/public/platform/Platform.h
@@ -414,10 +414,10 @@ public:
     // registerMemoryDumpProvider() method. |name| is used for debugging
     // (duplicates are allowed) and must be a long-lived C string.
     // See crbug.com/458295 for design docs.
-    virtual void registerMemoryDumpProvider(blink::WebMemoryDumpProvider*, const char* name) { }
+    BLINK_PLATFORM_EXPORT virtual void registerMemoryDumpProvider(blink::WebMemoryDumpProvider*, const char* name);
 
     // Must be called on the thread that called registerMemoryDumpProvider().
-    virtual void unregisterMemoryDumpProvider(blink::WebMemoryDumpProvider*) { }
+    BLINK_PLATFORM_EXPORT virtual void unregisterMemoryDumpProvider(blink::WebMemoryDumpProvider*);
 
     class TraceLogEnabledStateObserver {
     public:
@@ -430,9 +430,6 @@ public:
     virtual void addTraceLogEnabledStateObserver(TraceLogEnabledStateObserver*) {}
     virtual void removeTraceLogEnabledStateObserver(TraceLogEnabledStateObserver*) {}
 
-    // Returns a newly allocated WebProcessMemoryDump instance.
-    virtual blink::WebProcessMemoryDump* createProcessMemoryDump() { return nullptr; }
-
     typedef uint64_t WebMemoryAllocatorDumpGuid;
 
     // Returns guid corresponding to the given string (the hash value) for