[cc] Add nearest neighbor filtering for TextureLayer.

cc/resources/resource_provider.cc

Index: cc/resources/resource_provider.cc
diff --git a/cc/resources/resource_provider.cc b/cc/resources/resource_provider.cc
index 9651ef7939f0e33347b1976d89c308492df08858..d6c9ee7b63f4ab4e9a82d1d32e1354e9b97bc5ab 100644
--- a/cc/resources/resource_provider.cc
+++ b/cc/resources/resource_provider.cc
@@ -596,7 +596,7 @@ ResourceProvider::ResourceId ResourceProvider::CreateResourceFromTextureMailbox(
                         gfx::Size(),
                         Resource::External,
                         mailbox.target(),
-                        GL_LINEAR,
+                        mailbox.nearest_neighbor() ? GL_NEAREST : GL_LINEAR,

[danakj, 2014/11/04 21:30:23]

can you add a test to resource_provider_unittest.cc for this change to show it's
working?

[jackhou1, 2014/11/12 03:35:17]

I added a bit to ResourceProviderTest.TextureMailbox_GLTexture2D.

I realised it's possible for someone creating the mailbox to pass in a texture
with GL_LINEAR filters, but TextureMailbox::nearest_neighbor set to true. Would
it be better to set the filters on the texture here based on
TextureMailbox::nearest_neighbor, or set Resource::filter by checking what's set
on the texture?

[piman, 2014/11/12 04:43:26]

That's a user error then.
No, that would be redundant changes.
No, reading what's on the texture would involve a round-trip (slow).

                         0,
                         GL_CLAMP_TO_EDGE,
                         TextureHintImmutable,
@@ -616,7 +616,7 @@ ResourceProvider::ResourceId ResourceProvider::CreateResourceFromTextureMailbox(
                         shared_bitmap.release(),
                         mailbox.shared_memory_size(),
                         Resource::External,
-                        GL_LINEAR,
+                        mailbox.nearest_neighbor() ? GL_NEAREST : GL_LINEAR,
                         GL_CLAMP_TO_EDGE);
   }
   resource.allocated = true;
@@ -1335,7 +1335,7 @@ void ResourceProvider::ReceiveFromChild(
       resource = Resource(it->mailbox_holder.mailbox,
                           it->size,
                           Resource::Delegated,
-                          GL_LINEAR,
+                          it->filter,

[danakj, 2014/11/04 21:30:23]

can you add a test to resource_provider_unittest.cc for this change to show it's
working?

[jackhou1, 2014/11/12 03:35:17]

Huh, looks like Resource::filter is never read for anything if it's a software
resource. I guess the software renderer always assumes linear filtering? Is
there a way to force software rendering so I can fiddle with it?

[piman, 2014/11/12 04:43:26]

--disable-gpu

[jackhou1, 2014/11/12 05:05:53]

Looks like Patch Set 9 works fine with --disable-gpu. I guess blink is choosing
an already implemented code path.

                           it->is_repeated ? GL_REPEAT : GL_CLAMP_TO_EDGE);
     } else {
       resource = Resource(0,