Pluming for needs_push_properties for the impl tree.

This change ensures that pending tree is only synced
with the active tree if something has changed on the
pending tree.

Notable performance improvements to BrowserCompositorInvalidateLayerTreePerfTest

Before:
*RESULT layer_tree_host_frame_time: dense_layer_tree= 768.87890625 us

After:
*RESULT layer_tree_host_frame_time: dense_layer_tree= 655.21044921875 us

(run on a Galaxy Nexus running Android 4.3)
BUG=259511

Review URL: https://codereview.chromium.org/25896002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245734 0039d316-1c4b-4281-b951-d872f2087c98
Fix crash in feedback uploader in OTR.
Fix the feedback uploader factory to return the correct browser context even when incognito. This needs to be it's own instance, matching the incognito profile behavior of the feedback API.

R=zork@chromium.org
BUG=334557

Review URL: https://codereview.chromium.org/135153005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245735 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245735
cc: revert tile size increase for GPU rasterized layers.

It turned out the larger tiles only helped for some pages, but they regressed
performance for others. This patch changes the tile size for GPU rasterized
layers back to be identical with CPU rasterized layers.

The patch is only a partial revert of https://codereview.chromium.org/112263002/
Some changes were not reverted (including the unittest), because they are
still relevant (GPU rasterized layers don't have low-resolution tilings).

R=enne@chromium.org
BUG=325475

Review URL: https://codereview.chromium.org/141633006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245736 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245736