Move Renderer permanent callbacks into RendererClient interface.

We need to move the callbacks for video size and opacity change from
VideoFrameCompositor to VideoRenderer. Doing so will exceed the gmock
limit of 10 arguments for VideoRenderer::Initialize. This patch moves
the callbacks passed in VideoRenderer::Initialize into a RendererClient
interface so that additional callbacks can be added.

BUG=571155

Review-Url: https://codereview.chromium.org/1955843002
Cr-Commit-Position: refs/heads/master@{#393396}

• chromecast/browser/media/cast_renderer.cc[diff]
• chromecast/browser/media/cast_renderer.h[diff]
• chromecast/renderer/media/cma_renderer.cc[diff]
• chromecast/renderer/media/cma_renderer.h[diff]
• media/base/BUILD.gn[diff]
• media/base/audio_renderer.h[diff]
• media/base/mock_filters.cc[diff]
• media/base/mock_filters.h[diff]
• media/base/pipeline_impl.cc[diff]
• media/base/pipeline_impl.h[diff]
• media/base/pipeline_impl_unittest.cc[diff]
• media/base/renderer.h[diff]
• media/base/renderer_client.h[Added - diff]
• media/base/video_renderer.h[diff]
• media/mojo/services/mojo_renderer_impl.cc[diff]
• media/mojo/services/mojo_renderer_impl.h[diff]
• media/mojo/services/mojo_renderer_service.cc[diff]
• media/mojo/services/mojo_renderer_service.h[diff]
• media/renderers/audio_renderer_impl.cc[diff]
• media/renderers/audio_renderer_impl.h[diff]
• media/renderers/audio_renderer_impl_unittest.cc[diff]
• media/renderers/renderer_impl.cc[diff]
• media/renderers/renderer_impl.h[diff]
• media/renderers/renderer_impl_unittest.cc[diff]
• media/renderers/video_renderer_impl.cc[diff]
• media/renderers/video_renderer_impl.h[diff]
• media/renderers/video_renderer_impl_unittest.cc[diff]