[chromium] Use TextureLayerChromium for WebGL content instead of a dedicated layer...

[chromium] Use TextureLayerChromium for WebGL content instead of a dedicated layer type
https://bugs.webkit.org/show_bug.cgi?id=84311

Reviewed by Adrienne Walker.

Source/Platform:

Remove some unused getters.

* chromium/public/WebExternalTextureLayer.h:
(WebExternalTextureLayer):

Source/WebCore:

WebGL content's interface with the compositor can be expressed in terms of two basic operations:
1.) Do some stuff
2.) Provide a texture ID for the compositor to use

This implements (1) in DrawingBufferChromium and uses the already-existing TextureLayerChromium to handle (2).
This cuts down the compositor interface significantly and allows for more code reuse in exchange for more code
in TextureLayerChromium to handle the features WebGL needs.

* WebCore.gypi:
* platform/graphics/chromium/DrawingBufferChromium.cpp:
(WebCore::DrawingBuffer::~DrawingBuffer):
(DrawingBufferPrivate):
(WebCore::DrawingBufferPrivate::DrawingBufferPrivate):
(WebCore::DrawingBufferPrivate::~DrawingBufferPrivate):
(WebCore::DrawingBufferPrivate::layer):
(WebCore):
(WebCore::DrawingBuffer::platformLayer):
* platform/graphics/chromium/LayerRendererChromium.cpp:
* platform/graphics/chromium/TextureLayerChromium.h:
(TextureLayerChromiumClient):
(WebCore::TextureLayerChromiumClient::~TextureLayerChromiumClient):
(WebCore):
(TextureLayerChromium):
(WebCore::TextureLayerChromium::clearClient):
* platform/graphics/chromium/WebGLLayerChromium.cpp: Removed.
* platform/graphics/chromium/WebGLLayerChromium.h: Removed.
* platform/graphics/gpu/DrawingBuffer.h:
(WebCore):
(WebCore::DrawingBuffer::graphicsContext3D):
(DrawingBuffer):

Source/WebKit/chromium:

* WebKit.gypi:
* src/WebExternalTextureLayer.cpp:
(WebKit::WebExternalTextureLayer::create):
* src/WebLayer.cpp:
* tests/WebGLLayerChromiumTest.cpp: Removed.
* tests/WebLayerTest.cpp:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114983 268f45cc-cd09-0410-ab3c-d52691b4dbfc