[chromium] Scroll deltas should be floats
https://bugs.webkit.org/show_bug.cgi?id=111465

Reviewed by James Robinson.

This converts the remaining scroll delta fields to floats so that
we no longer lose precision due to DIP conversion. The natural
type for deltas is WebFloatSize, which was missing, so I also created
that type based on the existing WebSize header.

Source/Platform:

* Platform.gypi:
* chromium/public/WebFloatSize.h: Added.
(WebKit):
(WebFloatSize):
(WebKit::WebFloatSize::isEmpty):
(WebKit::WebFloatSize::WebFloatSize):
(WebKit::WebFloatSize::operator=):
(WebKit::WebFloatSize::operator WebCore::FloatSize):
(WebKit::WebFloatSize::operator gfx::SizeF):
(WebKit::WebFloatSize::operator gfx::Vector2dF):
(WebKit::operator==):
(WebKit::operator!=):
* chromium/public/WebGestureCurveTarget.h:
(WebKit::WebGestureCurveTarget::scrollBy):
(WebGestureCurveTarget):
* chromium/public/WebInputHandlerClient.h:
(WebKit::WebInputHandlerClient::scrollByIfPossible):
(WebInputHandlerClient):

Source/WebKit/chromium:

* src/WebCompositorInputHandlerImpl.cpp:
(WebKit::WebCompositorInputHandlerImpl::handleInputEventInternal):
(WebKit::WebCompositorInputHandlerImpl::touchpadFlingScroll):
(WebKit::WebCompositorInputHandlerImpl::scrollBy):
* src/WebCompositorInputHandlerImpl.h:
(WebCompositorInputHandlerImpl):
* src/WebViewImpl.cpp:
(WebKit::WebViewImpl::scrollBy):
* src/WebViewImpl.h:
(WebViewImpl):
* tests/WebCompositorInputHandlerImplTest.cpp:
(MockWebInputHandlerClient):
(WebKit::TEST_F):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@144856 268f45cc-cd09-0410-ab3c-d52691b4dbfc