webgl: optimize webgl.texSubImage2D(video) path.

media/blink/skcanvas_video_renderer.cc

Index: media/blink/skcanvas_video_renderer.cc
diff --git a/media/blink/skcanvas_video_renderer.cc b/media/blink/skcanvas_video_renderer.cc
index 132e0da7c6e521257c605cbeadb1adfd03a2ef8a..91367d419a390f64d4af365f6fa2dc52214d3e68 100644
--- a/media/blink/skcanvas_video_renderer.cc
+++ b/media/blink/skcanvas_video_renderer.cc
@@ -161,8 +161,10 @@ skia::RefPtr<SkImage> NewSkImageFromVideoFrameNative(
     DCHECK(source_texture);
     gl->BindTexture(GL_TEXTURE_2D, source_texture);
     SkCanvasVideoRenderer::CopyVideoFrameSingleTextureToGLTexture(
-        gl, video_frame, source_texture, GL_RGBA, GL_UNSIGNED_BYTE, true,
-        false);
+        gl, video_frame,
+        {SkCanvasVideoRenderer::CopyFrameSingleTextureParams::FullCopy,

[DaleCurtis, 2015/10/21 18:35:50]

Ditto.

+         GL_TEXTURE_2D, source_texture, GL_RGBA, GL_UNSIGNED_BYTE, 0, 0, 0,
+         true, false});
   } else {
     gl->WaitSyncPointCHROMIUM(mailbox_holder.sync_point);
     source_texture = gl->CreateAndConsumeTextureCHROMIUM(
@@ -546,11 +548,7 @@ void SkCanvasVideoRenderer::ConvertVideoFrameToRGBPixels(
 void SkCanvasVideoRenderer::CopyVideoFrameSingleTextureToGLTexture(
     gpu::gles2::GLES2Interface* gl,
     VideoFrame* video_frame,
-    unsigned int texture,
-    unsigned int internal_format,
-    unsigned int type,
-    bool premultiply_alpha,
-    bool flip_y) {
+    const CopyFrameSingleTextureParams& params) {
   DCHECK(video_frame);
   DCHECK(video_frame->HasTextures());
   DCHECK_EQ(1u, VideoFrame::NumPlanes(video_frame->format()));
@@ -571,9 +569,20 @@ void SkCanvasVideoRenderer::CopyVideoFrameSingleTextureToGLTexture(
   // value down to get the expected result.
   // "flip_y == true" means to reverse the video orientation while
   // "flip_y == false" means to keep the intrinsic orientation.
-  gl->CopyTextureCHROMIUM(GL_TEXTURE_2D, source_texture, texture,
-                          internal_format, type,
-                          flip_y, premultiply_alpha, false);
+  if (params.copy_type == CopyFrameSingleTextureParams::FullCopy) {
+    DCHECK(!params.xoffset && !params.yoffset);
+    gl->CopyTextureCHROMIUM(params.target, source_texture, params.texture,
+                            params.internal_format, params.type, params.flip_y,
+                            params.premultiply_alpha, false);
+  } else {
+    DCHECK_EQ(static_cast<unsigned int>(GL_FALSE), params.internal_format);
+    DCHECK_EQ(static_cast<unsigned int>(GL_FALSE), params.type);
+    gl->CopySubTextureCHROMIUM(params.target, source_texture, params.texture,
+                               params.xoffset, params.yoffset, 0, 0,
+                               video_frame->natural_size().width(),
+                               video_frame->natural_size().height(),
+                               params.flip_y, params.premultiply_alpha, false);
+  }
 
   gl->DeleteTextures(1, &source_texture);
   gl->Flush();