Revert of Refactoring: Move some classes from content/child to platform

content/child/blink_platform_impl.h

Index: content/child/blink_platform_impl.h
diff --git a/content/child/blink_platform_impl.h b/content/child/blink_platform_impl.h
index bdf839e255bb550b080bd6cfe1763ad4bf15fb71..d5129ef3dbee3b104a9906b8fe3f3a816e2f8ca2 100644
--- a/content/child/blink_platform_impl.h
+++ b/content/child/blink_platform_impl.h
@@ -51,6 +51,7 @@ class ThreadSafeSender;
 class TraceLogObserverAdapter;
 class WebCryptoImpl;
 class WebGeofencingProviderImpl;
+class WebMemoryDumpProviderAdapter;
 
 class CONTENT_EXPORT BlinkPlatformImpl
     : NON_EXPORTED_BASE(public blink::Platform) {
@@ -158,6 +159,9 @@ class CONTENT_EXPORT BlinkPlatformImpl
   base::ThreadLocalStorage::Slot current_thread_slot_;
   webcrypto::WebCryptoImpl web_crypto_;
   scoped_ptr<WebGeofencingProviderImpl> geofencing_provider_;
+  base::ScopedPtrHashMap<blink::WebMemoryDumpProvider*,
+                         scoped_ptr<WebMemoryDumpProviderAdapter>>
+      memory_dump_providers_;
   base::ScopedPtrHashMap<blink::Platform::TraceLogEnabledStateObserver*,
                          scoped_ptr<TraceLogObserverAdapter>>
       trace_log_observers_;