Gracefully handle drag cancellation during drag start.

Should the dispatching of a dragstart cause the drag to be reset, take
that into account when trying to handle follow-on drag operations.

The test is imported from https://bugs.webkit.org/show_bug.cgi?id=115296

R=dcheng@chromium.org
BUG=405442

Review URL: https://codereview.chromium.org/488923003

git-svn-id: svn://svn.chromium.org/blink/trunk@180646 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move HTMLInputElement method argument defaults into IDL file

The stepUp()/stepDown() methods' argument should default to 1, and the
setRangeText() method's selectionMode argument should default to
"preserve".

This matches the specification, and doesn't change behavior since these
defaults were already implemented in the C++ code.

BUG=258153

Review URL: https://codereview.chromium.org/471163006

git-svn-id: svn://svn.chromium.org/blink/trunk@180647 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Credential Manager: Migrate to WebView client-based approach.

In [1], jam@ suggested that we change the current approach of delivering
the core credential manager implementation via a Platform API piped
through //content. Instead, he proposed creating a client interface, and
setting that directly on the WebView from ChromeContentRendererClient.
This bypasses //content entirely, and makes the Chromium-side
implementation cleaner.

The Blink-side implementation gets a bit messier. In order to ensure
that credential manager doesn't introduce changes to core, this patch
introduces a new client interface in the module, and supplements Page
in order to make this interface available to the module's bindings code.
This is similar to the approach PrerendererClient has taken.

[1]: https://codereview.chromium.org/464883002/#msg9

BUG=400674

Review URL: https://codereview.chromium.org/488993003

git-svn-id: svn://svn.chromium.org/blink/trunk@180648 bbb929c8-8fbe-4397-9dbb-9b2b20218538
bindings: Adds installConditionallyEnabledProperties to
WrapperTypeInfo.

Adds installConditionallyEnabledProperties to
WrapperTypeInfo in addition to
installConditionallyEnabledMethods.  This is a preparation
to move 'wrap' function to ScriptWrappable.  Comming
ScriptWrappable::wrap needs to call
installConditionallyEnabledProperties without knowing V8T,
so we need it in WrapperTypeInfo.

BUG=235436

Review URL: https://codereview.chromium.org/491833002

git-svn-id: svn://svn.chromium.org/blink/trunk@180649 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: instantiate global models and ui components before target is added.

Review URL: https://codereview.chromium.org/493653002

git-svn-id: svn://svn.chromium.org/blink/trunk@180650 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rewrite inspector/timeline/timeline-frames.html to use actual frame signals

The older implementation used mocked signals that relied on old instrumentation
and non-threaded compositing, thus not adding much to the coverage.
This changes to actually producing frames using rAFs and displayAsyncThen(),
though for virtual/implsidepainting only, as content_shell presently uses
custom code path for compositing in DRT mode.

BUG=405460

Review URL: https://codereview.chromium.org/481513003

git-svn-id: svn://svn.chromium.org/blink/trunk@180651 bbb929c8-8fbe-4397-9dbb-9b2b20218538