Revert "Move WinPrecompile out of Source/WebKit/chromium"

This reverts https://src.chromium.org/viewvc/blink?view=revision&revision=155117

Broke the Windows build.

TBR=abarth

Review URL: https://codereview.chromium.org/21193002

git-svn-id: svn://svn.chromium.org/blink/trunk@155123 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Merge expectations files instead of overriding.

We still process each individual file the same way (e.g. duplicate lines
are an error, etc), but subsequent files in the expectations list
merge their results with the previous files instead of overriding.

This is implemented by adding each set of expectations into it's own TestExpectationsModel
and the merging them into the main one.

This will allow moving the Slow tests out into their own file and will make managing
the skia_test_expectations.txt file easier.

Review URL: https://chromiumcodereview.appspot.com/19898003

git-svn-id: svn://svn.chromium.org/blink/trunk@155124 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move plugin loading logic from SubframeLoader to HTMLPluginImageElement

BUG=none

Review URL: https://chromiumcodereview.appspot.com/21069004

git-svn-id: svn://svn.chromium.org/blink/trunk@155125 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move the WTF::SHA1 unit test to wtf/SHA1Test.cpp.

Previously it was run when its constructor was called in debug builds.
We have better ways of running unit tests now.

BUG=265623

Review URL: https://chromiumcodereview.appspot.com/21087004

git-svn-id: svn://svn.chromium.org/blink/trunk@155126 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove ContentDistributor::ensureDistribution

Instead of having this static method we should just do a recursive call up the tree inside
Element::ensureDistribution to update the distribution. This means we don't need to walk the
set of ElementShadows twice and also means that if you're 8+ levels down we don't need to do
any vector allocations. Doing this process recursively should be fine since attach() is
already recursive.

This is the first step in moving toward a recursive top down model for content distribution.

Review URL: https://chromiumcodereview.appspot.com/21123004

git-svn-id: svn://svn.chromium.org/blink/trunk@155127 bbb929c8-8fbe-4397-9dbb-9b2b20218538