webgl: optimize webgl.texSubImage2D(video) path.

third_party/WebKit/public/platform/WebMediaPlayer.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 146 matching lines @@
     virtual double mediaTimeForTimeValue(double timeValue) const = 0;
 
     virtual unsigned decodedFrameCount() const = 0;
     virtual unsigned droppedFrameCount() const = 0;
     virtual unsigned corruptedFrameCount() const { return 0; }
     virtual unsigned audioDecodedByteCount() const = 0;
     virtual unsigned videoDecodedByteCount() const = 0;
 
     virtual void paint(WebCanvas*, const WebRect&, unsigned char alpha, SkXfermode::Mode) = 0;
 
-    // TODO(dshwang): remove non-|target| version. crbug.com/349871
-    virtual bool copyVideoTextureToPlatformTexture(WebGraphicsContext3D*, unsigned texture, unsigned internalFormat, unsigned type, bool premultiplyAlpha, bool flipY) { return false; }
-
     // Do a GPU-GPU textures copy. If the copy is impossible or fails, it returns false.
-    virtual bool copyVideoTextureToPlatformTexture(WebGraphicsContext3D*, unsigned target,
-        unsigned texture, unsigned internalFormat, unsigned type, int level,
-        bool premultiplyAlpha, bool flipY) { return false; }
-    // Copy sub video frame texture to |texture|. If the copy is impossible or fails, it returns false.
-    virtual bool copyVideoSubTextureToPlatformTexture(WebGraphicsContext3D*, unsigned target,
-        unsigned texture, int level, int xoffset, int yoffset, bool premultiplyAlpha,
-        bool flipY) { return false; }
+    // Copy the video frame texture to full texture or sub texture depending on |copyType|.
+    // If FullCopy, |xoffset| and |yoffset| must be 0.
+    // If SubCopy, |internalFormat| and |type| must be GL_FALSE.
+    struct CopyVideoTextureParams {
+        enum CopyType { FullCopy, SubCopy };
+        CopyVideoTextureParams() = delete;

[philipj_slow, 2015/10/27 16:02:17]

Is this actually needed, doesn't declaring a constructor with arguments
implicitly get rid of the default constructor?

[dshwang, 2015/10/27 16:18:01]

good point. it's not needed. I removed it in the next patch set as well as in
chromium side struct.

+        CopyVideoTextureParams(CopyType copyType, unsigned target,
+            unsigned texture, unsigned internalFormat, unsigned type, int level,
+            int xoffset, int yoffset, bool premultiplyAlpha, bool flipY)
+            : copyType(copyType), target(target), texture(texture)
+            , internalFormat(internalFormat) , type(type), level(level)
+            , xoffset(xoffset), yoffset(yoffset)
+            , premultiplyAlpha(premultiplyAlpha), flipY(flipY)
+        { }
+        CopyType copyType;
+        unsigned target;
+        unsigned texture;
+        unsigned internalFormat;
+        unsigned type;
+        int level;
+        int xoffset;
+        int yoffset;
+        bool premultiplyAlpha;
+        bool flipY;
+    };
+    virtual bool copyVideoTextureToPlatformTexture(WebGraphicsContext3D*, const CopyVideoTextureParams&) = 0;
 
     virtual WebAudioSourceProvider* audioSourceProvider() { return nullptr; }
 
     // Returns whether keySystem is supported. If true, the result will be
     // reported by an event.
     virtual MediaKeyException generateKeyRequest(const WebString& keySystem, const unsigned char* initData, unsigned initDataLength) { return MediaKeyExceptionKeySystemNotSupported; }
     virtual MediaKeyException addKey(const WebString& keySystem, const unsigned char* key, unsigned keyLength, const unsigned char* initData, unsigned initDataLength, const WebString& sessionId) { return MediaKeyExceptionKeySystemNotSupported; }
     virtual MediaKeyException cancelKeyRequest(const WebString& keySystem, const WebString& sessionId) { return MediaKeyExceptionKeySystemNotSupported; }
     virtual void setContentDecryptionModule(WebContentDecryptionModule* cdm, WebContentDecryptionModuleResult result) { result.completeWithError(WebContentDecryptionModuleExceptionNotSupportedError, 0, "ERROR"); }
 
     // Sets the poster image URL.
     virtual void setPoster(const WebURL& poster) { }
 
     // Whether the WebMediaPlayer supports overlay fullscreen video mode. When
     // this is true, the video layer will be removed from the layer tree when
     // entering fullscreen, and the WebMediaPlayer is responsible for displaying
     // the video in enterFullscreen().
     virtual bool supportsOverlayFullscreenVideo() { return false; }
     // Instruct WebMediaPlayer to enter/exit fullscreen.
     virtual void enterFullscreen() { }
 
     virtual void enabledAudioTracksChanged(const WebVector<TrackId>& enabledTrackIds) { }
     // |selectedTrackId| is null if no track is selected.
     virtual void selectedVideoTrackChanged(TrackId* selectedTrackId) { }
 };
 
 } // namespace blink
 
 #endif