Implemented GetWindowSnapshot on RenderViewImpl

This necessitated the relocation of the previous chrome::GrabWindowSnapshot code
to ui/snapshot, which has been turned into it's own component to avoid circular dependencies with aura.
A new variant of GrabWindowSnapshot, GrabViewSnapshot, has been added as well to facilitate easier usage by views. chrome::GrabWindowSnapshotForUser was left in place to accomodate existing calls
to the API, but now calls up to the ui/snapshot code.

This is a subset of the prior CL 11362023, which has been broken apart to facilitate easier reviews

BUG=157479

Review URL: https://chromiumcodereview.appspot.com/11399002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@173329 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ui/snapshot/snapshot_android.cc b/ui/snapshot/snapshot_android.cc
new file mode 100644
index 0000000..4e89c9d
--- /dev/null
+++ b/ui/snapshot/snapshot_android.cc
@@ -0,0 +1,25 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/snapshot/snapshot.h"
+
+#include "ui/gfx/rect.h"
+
+namespace ui {
+
+bool GrabViewSnapshot(gfx::NativeView view,
+                      std::vector<unsigned char>* png_representation,
+                      const gfx::Rect& snapshot_bounds) {
+  // TODO(bajones): Implement Android snapshot functionality
+  return false;
+}
+
+bool GrabWindowSnapshot(gfx::NativeWindow window,
+                        std::vector<unsigned char>* png_representation,
+                        const gfx::Rect& snapshot_bounds) {
+  // TODO(bajones): Implement Android snapshot functionality
+  return false;
+}
+
+}  // namespace ui