Invalidate m_image after GPU-GPU texture copy

third_party/WebKit/Source/platform/graphics/StaticBitmapImage.cpp

Index: third_party/WebKit/Source/platform/graphics/StaticBitmapImage.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.cpp b/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.cpp
index 3d85460343ee69b82b0ae05d01995c03eb727b2f..f0749631ef926b8f37c8cbbba487c7ab1f9fe037 100644
--- a/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.cpp
+++ b/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.cpp
@@ -113,6 +113,7 @@ void StaticBitmapImage::copyToTexture(WebGraphicsContext3DProvider* provider, GL
     gl->Flush();
     GLbyte syncToken[24];
     gl->GenSyncTokenCHROMIUM(fenceSync, syncToken);
+    m_image = nullptr;

[Justin Novosad, 2016/07/20 15:07:52]

I think a better place for this would be at the end of switchStorageToMailbox

[xidachen, 2016/07/20 15:28:24]

I don't think that would work. I tried, and what happened is this:
at the end of switchStorageToMailbox, we set m_image = nullptr;
After that, we need to call gl->CopyTextureCHROMIUM(), that fails with error: GL
ERROR :GL_INVALID_VALUE : glCopyTextureCHROMIUM: unknown texture id

I believe that in order to have a valid texture id, the m_image has to be alive.
Does that make sense?

[Justin Novosad, 2016/07/20 15:51:59]

Sorry. Here you need to call switchStorageToMailbox, and at the end of
switchStorageToMailbox is where you'd reset m_image to null.  The fix you have
now loses the texture forever.

Also, for clarity, I think textureIdForWebGL should be renamed
switchStorageToSkImageForWebGL

[xidachen, 2016/07/20 16:47:27]

Right, that makes perfect sense, changed in the new PS.

 }
 
 bool StaticBitmapImage::switchStorageToMailbox(WebGraphicsContext3DProvider* provider)