export blink::Platform symbols in shared_library builds

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 7ae10de4fbc32f54451af08fe7594ce94dd98c8e..280e8e17eaf4e8bb46343be808622911143ecbe3 100644
--- a/third_party/WebKit/public/platform/Platform.h
+++ b/third_party/WebKit/public/platform/Platform.h
@@ -123,7 +123,7 @@ class WebUnitTestSupport;
 struct WebLocalizedString;
 struct WebSize;
 
-class Platform {
+class BLINK_PLATFORM_EXPORT_CLASS Platform {

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

Just use BLINK_PLATFORM_EXPORT

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

This was a workaround to keep visual studio happy, alternatively I think we can
remote BLINK_PLATFORM_EXPORT from the members.

[dcheng, 2016/03/07 16:15:47]

That's OK, the export macros were never really meant to hide symbols in a shared
library build anyway.

[Mostyn Bramley-Moore, 2016/03/07 17:32:08]

I'm curious- what else do GCC visibility attributes do?

[dcheng, 2016/03/07 19:27:03]

I think this is the main thing (controlling symbol visibility). But in Chromium,
we just use it so that the shared library build works.

 public:
     // HTML5 Database ------------------------------------------------------
 
@@ -138,116 +138,116 @@ public:
     BLINK_PLATFORM_EXPORT static Platform* current();
 
     // May return null.
-    virtual WebCookieJar* cookieJar() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebCookieJar* cookieJar() { return nullptr; }

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

Why do we need to mark these as hidden? Why not just leave them the way they
are?

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

It's possible to do that, the only difference is that we might expose more
global symbols from the shared library.

 
     // Must return non-null.
-    virtual WebClipboard* clipboard() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebClipboard* clipboard() { return nullptr; }
 
     // Must return non-null.
-    virtual WebFileUtilities* fileUtilities() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebFileUtilities* fileUtilities() { return nullptr; }
 
     // Must return non-null.
-    virtual WebMimeRegistry* mimeRegistry() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebMimeRegistry* mimeRegistry() { return nullptr; }
 
     // May return null if sandbox support is not necessary
-    virtual WebSandboxSupport* sandboxSupport() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebSandboxSupport* sandboxSupport() { return nullptr; }
 
     // May return null on some platforms.
-    virtual WebThemeEngine* themeEngine() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebThemeEngine* themeEngine() { return nullptr; }
 
-    virtual WebFallbackThemeEngine* fallbackThemeEngine() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebFallbackThemeEngine* fallbackThemeEngine() { return nullptr; }
 
     // May return null.
-    virtual WebSpeechSynthesizer* createSpeechSynthesizer(WebSpeechSynthesizerClient*) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebSpeechSynthesizer* createSpeechSynthesizer(WebSpeechSynthesizerClient*) { return nullptr; }
 
 
     // Audio --------------------------------------------------------------
 
-    virtual double audioHardwareSampleRate() { return 0; }
-    virtual size_t audioHardwareBufferSize() { return 0; }
-    virtual unsigned audioHardwareOutputChannels() { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual double audioHardwareSampleRate() { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual size_t audioHardwareBufferSize() { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual unsigned audioHardwareOutputChannels() { return 0; }
 
     // Creates a device for audio I/O.
     // Pass in (numberOfInputChannels > 0) if live/local audio input is desired.
-    virtual WebAudioDevice* createAudioDevice(size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfChannels, double sampleRate, WebAudioDevice::RenderCallback*, const WebString& deviceId, const WebSecurityOrigin&) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebAudioDevice* createAudioDevice(size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfChannels, double sampleRate, WebAudioDevice::RenderCallback*, const WebString& deviceId, const WebSecurityOrigin&) { return nullptr; }
 
 
     // MIDI ----------------------------------------------------------------
 
     // Creates a platform dependent WebMIDIAccessor. MIDIAccessor under platform
     // creates and owns it.
-    virtual WebMIDIAccessor* createMIDIAccessor(WebMIDIAccessorClient*) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebMIDIAccessor* createMIDIAccessor(WebMIDIAccessorClient*) { return nullptr; }
 
 
     // Blob ----------------------------------------------------------------
 
     // Must return non-null.
-    virtual WebBlobRegistry* blobRegistry() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebBlobRegistry* blobRegistry() { return nullptr; }
 
     // Database ------------------------------------------------------------
 
     // Opens a database file; dirHandle should be 0 if the caller does not need
     // a handle to the directory containing this file
-    virtual FileHandle databaseOpenFile(const WebString& vfsFileName, int desiredFlags) { return FileHandle(); }
+    BLINK_PLATFORM_HIDDEN virtual FileHandle databaseOpenFile(const WebString& vfsFileName, int desiredFlags) { return FileHandle(); }
 
     // Deletes a database file and returns the error code
-    virtual int databaseDeleteFile(const WebString& vfsFileName, bool syncDir) { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual int databaseDeleteFile(const WebString& vfsFileName, bool syncDir) { return 0; }
 
     // Returns the attributes of the given database file
-    virtual long databaseGetFileAttributes(const WebString& vfsFileName) { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual long databaseGetFileAttributes(const WebString& vfsFileName) { return 0; }
 
     // Returns the size of the given database file
-    virtual long long databaseGetFileSize(const WebString& vfsFileName) { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual long long databaseGetFileSize(const WebString& vfsFileName) { return 0; }
 
     // Returns the space available for the given origin
-    virtual long long databaseGetSpaceAvailableForOrigin(const WebString& originIdentifier) { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual long long databaseGetSpaceAvailableForOrigin(const WebString& originIdentifier) { return 0; }
 
     // Set the size of the given database file
-    virtual bool databaseSetFileSize(const WebString& vfsFileName, long long size) { return false; }
+    BLINK_PLATFORM_HIDDEN virtual bool databaseSetFileSize(const WebString& vfsFileName, long long size) { return false; }
 
 
     // DOM Storage --------------------------------------------------
 
     // Return a LocalStorage namespace
-    virtual WebStorageNamespace* createLocalStorageNamespace() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebStorageNamespace* createLocalStorageNamespace() { return nullptr; }
 
 
     // FileSystem ----------------------------------------------------------
 
     // Must return non-null.
-    virtual WebFileSystem* fileSystem() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebFileSystem* fileSystem() { return nullptr; }
 
 
     // IDN conversion ------------------------------------------------------
 
-    virtual WebString convertIDNToUnicode(const WebString& host, const WebString& languages) { return host; }
+    BLINK_PLATFORM_HIDDEN virtual WebString convertIDNToUnicode(const WebString& host, const WebString& languages) { return host; }
 
 
     // IndexedDB ----------------------------------------------------------
 
     // Must return non-null.
-    virtual WebIDBFactory* idbFactory() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebIDBFactory* idbFactory() { return nullptr; }
 
 
     // Cache Storage ----------------------------------------------------------
 
     // The caller is responsible for deleting the returned object.
-    virtual WebServiceWorkerCacheStorage* cacheStorage(const WebSecurityOrigin&) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebServiceWorkerCacheStorage* cacheStorage(const WebSecurityOrigin&) { return nullptr; }
 
     // Gamepad -------------------------------------------------------------
 
-    virtual void sampleGamepads(WebGamepads& into) { into.length = 0; }
+    BLINK_PLATFORM_HIDDEN virtual void sampleGamepads(WebGamepads& into) { into.length = 0; }
 
     // History -------------------------------------------------------------
 
     // Returns the hash for the given canonicalized URL for use in visited
     // link coloring.
-    virtual unsigned long long visitedLinkHash(
+    BLINK_PLATFORM_HIDDEN virtual unsigned long long visitedLinkHash(
         const char* canonicalURL, size_t length) { return 0; }
 
     // Returns whether the given link hash is in the user's history. The
     // hash must have been generated by calling VisitedLinkHash().
-    virtual bool isLinkVisited(unsigned long long linkHash) { return false; }
+    BLINK_PLATFORM_HIDDEN virtual bool isLinkVisited(unsigned long long linkHash) { return false; }
 
 
     // Keygen --------------------------------------------------------------
@@ -256,121 +256,121 @@ public:
     // Returns a base64 encoded signed copy of a public key from a newly
     // generated key pair and the supplied challenge string. keySizeindex
     // specifies the strength of the key.
-    virtual WebString signedPublicKeyAndChallengeString(
+    BLINK_PLATFORM_HIDDEN virtual WebString signedPublicKeyAndChallengeString(
         unsigned keySizeIndex, const WebString& challenge, const WebURL& url, const WebURL& topOrigin)
     {
         return WebString();
     }
 
     // Same as above, but always returns actual value, without any caches.
-    virtual size_t actualMemoryUsageMB() { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual size_t actualMemoryUsageMB() { return 0; }
 
     // Return the number of of processors of the current machine.
-    virtual size_t numberOfProcessors() { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual size_t numberOfProcessors() { return 0; }
 
     // Allocates discardable memory. May return nullptr, even if the platform supports
     // discardable memory. If nonzero, however, then the WebDiscardableMmeory is
     // returned in an locked state. You may use its underlying data() member
     // directly, taking care to unlock it when you are ready to let it become
     // discardable.
-    virtual WebDiscardableMemory* allocateAndLockDiscardableMemory(size_t bytes) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebDiscardableMemory* allocateAndLockDiscardableMemory(size_t bytes) { return nullptr; }
 
-    static const size_t noDecodedImageByteLimit = static_cast<size_t>(-1);
+    BLINK_PLATFORM_HIDDEN static const size_t noDecodedImageByteLimit = static_cast<size_t>(-1);
 
     // Returns the maximum amount of memory a decoded image should be allowed.
     // See comments on ImageDecoder::m_maxDecodedBytes.
-    virtual size_t maxDecodedImageBytes() { return noDecodedImageByteLimit; }
+    BLINK_PLATFORM_HIDDEN virtual size_t maxDecodedImageBytes() { return noDecodedImageByteLimit; }
 
     // Process -------------------------------------------------------------
 
     // Returns a unique identifier for a process. This may not necessarily be
     // the process's process ID.
-    virtual uint32_t getUniqueIdForProcess() { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual uint32_t getUniqueIdForProcess() { return 0; }
 
 
     // Message Ports -------------------------------------------------------
 
     // Creates a Message Port Channel pair. This can be called on any thread.
     // The returned objects should only be used on the thread they were created on.
-    virtual void createMessageChannel(WebMessagePortChannel** channel1, WebMessagePortChannel** channel2) { *channel1 = 0; *channel2 = 0; }
+    BLINK_PLATFORM_HIDDEN virtual void createMessageChannel(WebMessagePortChannel** channel1, WebMessagePortChannel** channel2) { *channel1 = 0; *channel2 = 0; }
 
 
     // Network -------------------------------------------------------------
 
     // Returns a new WebURLLoader instance.
-    virtual WebURLLoader* createURLLoader() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebURLLoader* createURLLoader() { return nullptr; }
 
     // May return null.
-    virtual WebPrescientNetworking* prescientNetworking() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebPrescientNetworking* prescientNetworking() { return nullptr; }
 
     // Returns a new WebSocketHandle instance.
-    virtual WebSocketHandle* createWebSocketHandle() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebSocketHandle* createWebSocketHandle() { return nullptr; }
 
     // Returns the User-Agent string.
-    virtual WebString userAgent() { return WebString(); }
+    BLINK_PLATFORM_HIDDEN virtual WebString userAgent() { return WebString(); }
 
     // A suggestion to cache this metadata in association with this URL.
-    virtual void cacheMetadata(const WebURL&, int64_t responseTime, const char* data, size_t dataSize) { }
+    BLINK_PLATFORM_HIDDEN virtual void cacheMetadata(const WebURL&, int64_t responseTime, const char* data, size_t dataSize) { }
 
     // Returns the decoded data url if url had a supported mimetype and parsing was successful.
-    virtual WebData parseDataURL(const WebURL&, WebString& mimetype, WebString& charset) { return WebData(); }
+    BLINK_PLATFORM_HIDDEN virtual WebData parseDataURL(const WebURL&, WebString& mimetype, WebString& charset) { return WebData(); }
 
-    virtual WebURLError cancelledError(const WebURL&) const { return WebURLError(); }
+    BLINK_PLATFORM_HIDDEN virtual WebURLError cancelledError(const WebURL&) const { return WebURLError(); }
 
-    virtual bool isReservedIPAddress(const WebString& host) const { return false; }
+    BLINK_PLATFORM_HIDDEN virtual bool isReservedIPAddress(const WebString& host) const { return false; }
 
-    virtual bool portAllowed(const WebURL&) const { return false; }
+    BLINK_PLATFORM_HIDDEN virtual bool portAllowed(const WebURL&) const { return false; }
 
     // Plugins -------------------------------------------------------------
 
     // If refresh is true, then cached information should not be used to
     // satisfy this call.
-    virtual void getPluginList(bool refresh, WebPluginListBuilder*) { }
+    BLINK_PLATFORM_HIDDEN virtual void getPluginList(bool refresh, WebPluginListBuilder*) { }
 
 
     // Public Suffix List --------------------------------------------------
 
     // May return null on some platforms.
-    virtual WebPublicSuffixList* publicSuffixList() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebPublicSuffixList* publicSuffixList() { return nullptr; }
 
 
     // Resources -----------------------------------------------------------
 
     // Returns a localized string resource (with substitution parameters).
-    virtual WebString queryLocalizedString(WebLocalizedString::Name) { return WebString(); }
-    virtual WebString queryLocalizedString(WebLocalizedString::Name, const WebString& parameter) { return WebString(); }
-    virtual WebString queryLocalizedString(WebLocalizedString::Name, const WebString& parameter1, const WebString& parameter2) { return WebString(); }
+    BLINK_PLATFORM_HIDDEN virtual WebString queryLocalizedString(WebLocalizedString::Name) { return WebString(); }
+    BLINK_PLATFORM_HIDDEN virtual WebString queryLocalizedString(WebLocalizedString::Name, const WebString& parameter) { return WebString(); }
+    BLINK_PLATFORM_HIDDEN virtual WebString queryLocalizedString(WebLocalizedString::Name, const WebString& parameter1, const WebString& parameter2) { return WebString(); }
 
 
     // Threads -------------------------------------------------------
 
     // Creates an embedder-defined thread.
-    virtual WebThread* createThread(const char* name) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebThread* createThread(const char* name) { return nullptr; }
 
     // Returns an interface to the current thread. This is owned by the
     // embedder.
-    virtual WebThread* currentThread() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebThread* currentThread() { return nullptr; }
 
     // Resources -----------------------------------------------------------
 
     // Returns a blob of data corresponding to the named resource.
-    virtual WebData loadResource(const char* name) { return WebData(); }
+    BLINK_PLATFORM_HIDDEN virtual WebData loadResource(const char* name) { return WebData(); }
 
     // Decodes the in-memory audio file data and returns the linear PCM audio data in the destinationBus.
     // A sample-rate conversion to sampleRate will occur if the file data is at a different sample-rate.
     // Returns true on success.
-    virtual bool loadAudioResource(WebAudioBus* destinationBus, const char* audioFileData, size_t dataSize) { return false; }
+    BLINK_PLATFORM_HIDDEN virtual bool loadAudioResource(WebAudioBus* destinationBus, const char* audioFileData, size_t dataSize) { return false; }
 
     // Screen -------------------------------------------------------------
 
     // Supplies the system monitor color profile.
-    virtual void screenColorProfile(WebVector<char>* profile) { }
+    BLINK_PLATFORM_HIDDEN virtual void screenColorProfile(WebVector<char>* profile) { }
 
 
     // Scrollbar ----------------------------------------------------------
 
     // Must return non-null.
-    virtual WebScrollbarBehavior* scrollbarBehavior() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebScrollbarBehavior* scrollbarBehavior() { return nullptr; }
 
 
     // Sudden Termination --------------------------------------------------
@@ -378,46 +378,46 @@ public:
     // Disable/Enable sudden termination on a process level. When possible, it
     // is preferable to disable sudden termination on a per-frame level via
     // WebFrameClient::suddenTerminationDisablerChanged.
-    virtual void suddenTerminationChanged(bool enabled) { }
+    BLINK_PLATFORM_HIDDEN virtual void suddenTerminationChanged(bool enabled) { }
 
 
     // System --------------------------------------------------------------
 
     // Returns a value such as "en-US".
-    virtual WebString defaultLocale() { return WebString(); }
+    BLINK_PLATFORM_HIDDEN virtual WebString defaultLocale() { return WebString(); }
 
     // Returns an interface to the main thread. Can be null if blink was initialized on a thread without a message loop.
     BLINK_PLATFORM_EXPORT WebThread* mainThread() const;
 
     // Returns an interface to the compositor thread. This can be null if the
     // renderer was created with threaded rendering desabled.
-    virtual WebThread* compositorThread() const { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual WebThread* compositorThread() const { return 0; }
 
     // Vibration -----------------------------------------------------------
 
     // Starts a vibration for the given duration in milliseconds. If there is currently an active
     // vibration it will be cancelled before the new one is started.
-    virtual void vibrate(unsigned time) { }
+    BLINK_PLATFORM_HIDDEN virtual void vibrate(unsigned time) { }
 
     // Cancels the current vibration, if there is one.
-    virtual void cancelVibration() { }
+    BLINK_PLATFORM_HIDDEN virtual void cancelVibration() { }
 
 
     // Testing -------------------------------------------------------------
 
     // Get a pointer to testing support interfaces. Will not be available in production builds.
-    virtual WebUnitTestSupport* unitTestSupport() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebUnitTestSupport* unitTestSupport() { return nullptr; }
 
     // Record to a RAPPOR privacy-preserving metric, see: https://www.chromium.org/developers/design-documents/rappor.
     // recordRappor records a sample string, while recordRapporURL records the domain and registry of a url.
-    virtual void recordRappor(const char* metric, const WebString& sample) { }
-    virtual void recordRapporURL(const char* metric, const blink::WebURL& url) { }
+    BLINK_PLATFORM_HIDDEN virtual void recordRappor(const char* metric, const WebString& sample) { }
+    BLINK_PLATFORM_HIDDEN virtual void recordRapporURL(const char* metric, const blink::WebURL& url) { }
 
     // Record a UMA sequence action.  The UserMetricsAction construction must
     // be on a single line for extract_actions.py to find it.  Please see
     // that script for more details.  Intended use is:
     // recordAction(UserMetricsAction("MyAction"))
-    virtual void recordAction(const UserMetricsAction&) { }
+    BLINK_PLATFORM_HIDDEN virtual void recordAction(const UserMetricsAction&) { }
 
     // Registers a memory dump provider. The WebMemoryDumpProvider::onMemoryDump
     // method will be called on the same thread that called the
@@ -429,7 +429,7 @@ public:
     // Must be called on the thread that called registerMemoryDumpProvider().
     BLINK_PLATFORM_EXPORT virtual void unregisterMemoryDumpProvider(blink::WebMemoryDumpProvider*);
 
-    class TraceLogEnabledStateObserver {
+    class BLINK_PLATFORM_HIDDEN TraceLogEnabledStateObserver {
     public:
         virtual ~TraceLogEnabledStateObserver() = default;
         virtual void onTraceLogEnabled() = 0;
@@ -437,77 +437,77 @@ public:
     };
 
     // Register or unregister a trace log state observer. Does not take ownership.
-    virtual void addTraceLogEnabledStateObserver(TraceLogEnabledStateObserver*) {}
-    virtual void removeTraceLogEnabledStateObserver(TraceLogEnabledStateObserver*) {}
+    BLINK_PLATFORM_HIDDEN virtual void addTraceLogEnabledStateObserver(TraceLogEnabledStateObserver*) {}
+    BLINK_PLATFORM_HIDDEN virtual void removeTraceLogEnabledStateObserver(TraceLogEnabledStateObserver*) {}
 
     typedef uint64_t WebMemoryAllocatorDumpGuid;
 
     // Returns guid corresponding to the given string (the hash value) for
     // creating a WebMemoryAllocatorDump.
-    virtual WebMemoryAllocatorDumpGuid createWebMemoryAllocatorDumpGuid(const WebString& guidStr) { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual WebMemoryAllocatorDumpGuid createWebMemoryAllocatorDumpGuid(const WebString& guidStr) { return 0; }
 
     // GPU ----------------------------------------------------------------
     //
     // May return null if GPU is not supported.
     // Returns newly allocated and initialized offscreen WebGraphicsContext3D instance.
     // Passing an existing context to shareContext will create the new context in the same share group as the passed context.
-    virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&, WebGraphicsContext3D* shareContext) { return nullptr; }
-    virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&, WebGraphicsContext3D* shareContext, WebGraphicsContext3D::WebGraphicsInfo* glInfo) { return nullptr; }
-    virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&, WebGraphicsContext3D* shareContext) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&, WebGraphicsContext3D* shareContext, WebGraphicsContext3D::WebGraphicsInfo* glInfo) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&) { return nullptr; }
 
     // Returns a newly allocated and initialized offscreen context provider. The provider may return a null
     // graphics context if GPU is not supported.
-    virtual WebGraphicsContext3DProvider* createSharedOffscreenGraphicsContext3DProvider() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebGraphicsContext3DProvider* createSharedOffscreenGraphicsContext3DProvider() { return nullptr; }
 
     // Returns true if the platform is capable of producing an offscreen context suitable for accelerating 2d canvas.
     // This will return false if the platform cannot promise that contexts will be preserved across operations like
     // locking the screen or if the platform cannot provide a context with suitable performance characteristics.
     //
     // This value must be checked again after a context loss event as the platform's capabilities may have changed.
-    virtual bool canAccelerate2dCanvas() { return false; }
+    BLINK_PLATFORM_HIDDEN virtual bool canAccelerate2dCanvas() { return false; }
 
-    virtual bool isThreadedCompositingEnabled() { return false; }
-    virtual bool isThreadedAnimationEnabled() { return true; }
+    BLINK_PLATFORM_HIDDEN virtual bool isThreadedCompositingEnabled() { return false; }
+    BLINK_PLATFORM_HIDDEN virtual bool isThreadedAnimationEnabled() { return true; }
 
-    virtual WebCompositorSupport* compositorSupport() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebCompositorSupport* compositorSupport() { return nullptr; }
 
-    virtual WebFlingAnimator* createFlingAnimator() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebFlingAnimator* createFlingAnimator() { return nullptr; }
 
     // Creates a new fling animation curve instance for device |deviceSource|
     // with |velocity| and already scrolled |cumulativeScroll| pixels.
-    virtual WebGestureCurve* createFlingAnimationCurve(WebGestureDevice deviceSource, const WebFloatPoint& velocity, const WebSize& cumulativeScroll) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebGestureCurve* createFlingAnimationCurve(WebGestureDevice deviceSource, const WebFloatPoint& velocity, const WebSize& cumulativeScroll) { return nullptr; }
 
     // WebRTC ----------------------------------------------------------
 
     // Creates an WebRTCPeerConnectionHandler for RTCPeerConnection.
     // May return null if WebRTC functionality is not avaliable or if it's out of resources.
-    virtual WebRTCPeerConnectionHandler* createRTCPeerConnectionHandler(WebRTCPeerConnectionHandlerClient*) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebRTCPeerConnectionHandler* createRTCPeerConnectionHandler(WebRTCPeerConnectionHandlerClient*) { return nullptr; }
 
     // Creates an WebMediaRecorderHandler to record MediaStreams.
     // May return null if the functionality is not available or out of resources.
-    virtual WebMediaRecorderHandler* createMediaRecorderHandler() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebMediaRecorderHandler* createMediaRecorderHandler() { return nullptr; }
 
     // May return null if WebRTC functionality is not available or out of resources.
-    virtual WebRTCCertificateGenerator* createRTCCertificateGenerator() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebRTCCertificateGenerator* createRTCCertificateGenerator() { return nullptr; }
 
     // May return null if WebRTC functionality is not available or out of resources.
-    virtual WebMediaStreamCenter* createMediaStreamCenter(WebMediaStreamCenterClient*) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebMediaStreamCenter* createMediaStreamCenter(WebMediaStreamCenterClient*) { return nullptr; }
 
     // Creates an WebCanvasCaptureHandler to capture Canvas output.
-    virtual WebCanvasCaptureHandler* createCanvasCaptureHandler(const WebSize&, double, WebMediaStreamTrack*) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebCanvasCaptureHandler* createCanvasCaptureHandler(const WebSize&, double, WebMediaStreamTrack*) { return nullptr; }
 
     // Fills in the WebMediaStream to capture from the WebMediaPlayer identified
     // by the second parameter.
-    virtual void createHTMLVideoElementCapturer(WebMediaStream*, WebMediaPlayer*) {}
+    BLINK_PLATFORM_HIDDEN virtual void createHTMLVideoElementCapturer(WebMediaStream*, WebMediaPlayer*) {}
 
     // WebWorker ----------------------------------------------------------
 
-    virtual void didStartWorkerThread() { }
-    virtual void willStopWorkerThread() { }
+    BLINK_PLATFORM_HIDDEN virtual void didStartWorkerThread() { }
+    BLINK_PLATFORM_HIDDEN virtual void willStopWorkerThread() { }
 
     // WebCrypto ----------------------------------------------------------
 
-    virtual WebCrypto* crypto() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebCrypto* crypto() { return nullptr; }
 
 
     // Platform events -----------------------------------------------------
@@ -519,39 +519,39 @@ public:
     {
         connectToRemoteService(Interface::Name_, ptr.PassMessagePipe());
     }
-    virtual void connectToRemoteService(const char* name, mojo::ScopedMessagePipeHandle handle) { }
+    BLINK_PLATFORM_HIDDEN virtual void connectToRemoteService(const char* name, mojo::ScopedMessagePipeHandle handle) { }
 
     // Request the platform to start listening to the events of the specified
     // type and notify the given listener (if not null) when there is an update.
-    virtual void startListening(WebPlatformEventType type, WebPlatformEventListener* listener) { }
+    BLINK_PLATFORM_HIDDEN virtual void startListening(WebPlatformEventType type, WebPlatformEventListener* listener) { }
 
     // Request the platform to stop listening to the specified event and no
     // longer notify the listener, if any.
-    virtual void stopListening(WebPlatformEventType type) { }
+    BLINK_PLATFORM_HIDDEN virtual void stopListening(WebPlatformEventType type) { }
 
     // This method converts from the supplied DOM code enum to the
     // embedder's DOM code value for the key pressed. |domCode| values are
     // based on the value defined in ui/events/keycodes/dom4/keycode_converter_data.h.
     // Returns null string, if DOM code value is not found.
-    virtual WebString domCodeStringFromEnum(int domCode) { return WebString(); }
+    BLINK_PLATFORM_HIDDEN virtual WebString domCodeStringFromEnum(int domCode) { return WebString(); }
 
     // This method converts from the suppled DOM code value to the
     // embedder's DOM code enum for the key pressed. |codeString| is defined in
     // ui/events/keycodes/dom4/keycode_converter_data.h.
     // Returns 0, if DOM code enum is not found.
-    virtual int domEnumFromCodeString(const WebString& codeString) { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual int domEnumFromCodeString(const WebString& codeString) { return 0; }
 
     // This method converts from the supplied DOM |key| enum to the
     // corresponding DOM |key| string value for the key pressed. |domKey| values are
     // based on the value defined in ui/events/keycodes/dom3/dom_key_data.h.
     // Returns empty string, if DOM key value is not found.
-    virtual WebString domKeyStringFromEnum(int domKey) { return WebString(); }
+    BLINK_PLATFORM_HIDDEN virtual WebString domKeyStringFromEnum(int domKey) { return WebString(); }
 
     // This method converts from the suppled DOM |key| value to the
     // embedder's DOM |key| enum for the key pressed. |keyString| is defined in
     // ui/events/keycodes/dom3/dom_key_data.h.
     // Returns 0 if DOM key enum is not found.
-    virtual int domKeyEnumFromString(const WebString& keyString) { return 0; }
+    BLINK_PLATFORM_HIDDEN virtual int domKeyEnumFromString(const WebString& keyString) { return 0; }
 
     // Quota -----------------------------------------------------------
 
@@ -560,7 +560,7 @@ public:
     // with the current usage and quota information for the partition. When
     // an error occurs WebStorageQuotaCallbacks::didFail is called with an
     // error code.
-    virtual void queryStorageUsageAndQuota(
+    BLINK_PLATFORM_HIDDEN virtual void queryStorageUsageAndQuota(
         const WebURL& storagePartition,
         WebStorageQuotaType,
         WebStorageQuotaCallbacks) { }
@@ -568,49 +568,49 @@ public:
 
     // WebDatabase --------------------------------------------------------
 
-    virtual WebDatabaseObserver* databaseObserver() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebDatabaseObserver* databaseObserver() { return nullptr; }
 
 
     // Web Notifications --------------------------------------------------
 
-    virtual WebNotificationManager* notificationManager() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebNotificationManager* notificationManager() { return nullptr; }
 
 
     // Geofencing ---------------------------------------------------------
 
-    virtual WebGeofencingProvider* geofencingProvider() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebGeofencingProvider* geofencingProvider() { return nullptr; }
 
 
     // Push API------------------------------------------------------------
 
-    virtual WebPushProvider* pushProvider() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebPushProvider* pushProvider() { return nullptr; }
 
 
     // navigator.connect --------------------------------------------------
 
-    virtual WebNavigatorConnectProvider* navigatorConnectProvider() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebNavigatorConnectProvider* navigatorConnectProvider() { return nullptr; }
 
     // Returns pointer to a new blink owned WebServicePortProvider instance,
     // associated with a particular ServicePortCollection (identified by the
     // WebServicePortProviderClient passed in).
-    virtual WebServicePortProvider* createServicePortProvider(WebServicePortProviderClient*) { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebServicePortProvider* createServicePortProvider(WebServicePortProviderClient*) { return nullptr; }
 
     // Permissions --------------------------------------------------------
 
-    virtual WebPermissionClient* permissionClient() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebPermissionClient* permissionClient() { return nullptr; }
 
 
     // Background Sync API------------------------------------------------------------
 
-    virtual WebSyncProvider* backgroundSyncProvider() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebSyncProvider* backgroundSyncProvider() { return nullptr; }
 
     // Experimental Framework ----------------------------------------------
 
-    virtual WebTrialTokenValidator* trialTokenValidator() { return nullptr; }
+    BLINK_PLATFORM_HIDDEN virtual WebTrialTokenValidator* trialTokenValidator() { return nullptr; }
 
 protected:
     BLINK_PLATFORM_EXPORT Platform();
-    virtual ~Platform() { }
+    BLINK_PLATFORM_HIDDEN virtual ~Platform() { }
 
     WebThread* m_mainThread;
 };