Allow specification of the FLX bundle (containing no Dart snapshot) outside the iOS/Mac application bundle.

Allows launching of apps without having any Xcodebuild step in the simulator.

The FLX will contain a font manifest JSON file that maps font family names
to custom font assets.  Flutter will provide a FontSelector that loads
fonts on demand and caches typeface and style data.

We now use std::unique_ptr more consistently.

We have enough geometry classes kicking around. We don't need the
ui/gfx/geometry types too.

Now that the compositor doesn't have any tricky deps, we can make it a
top-level project, which saves a bunch of typing.

* Start capturing via <obs_host>:<obs_port>/flutter_startTracing
* Stop capturing via <obs_host>:<obs_port>/flutter_stopTracing

Also, remove the --snapshot flag because using FLX files is the path we're
paving.

We now respect the "route" field in Intents to load a route other than '/'.
Also, use popRoute rather than events to indicate that the framework has asked
us to go back.

Now the control flow for wiring up platform services starts in the
platform-specific code. Previously we started in shared code, which was
imposing constraints on the startup sequence for all platforms. Now that we
start in platform-specific code, we'll be able to add better support for Mojo
in a future patch.

We weren't using the network service for anything.

After this patch, we can execute Dart code and draw the result via MGL. We
still need to plumb in services.

After this patch, we can execute Dart code an create an X window. There's a
sketch of some graphics code, but it's not wired up yet.

Currently this code isn't completely wired up, but this patch is an incremental
step in that direction.

dont mutate from frame to frame

Instead of squashing the layers down into a single SkPicture, we now pass the
tree to the GPU thread, which draws everything separately.

We don't use this interface yet.

Previously we were using the cull rect of the SkPicture to size the GPU buffer,
but Skia is too smart and shrinkwraps the cull rect, which meant we weren't
sizing the GPU buffer to the right size.

Fixes #814

traces from base and the shell view dart isolate simultaneously.
Trace files contain samples from multiple sources and must be merged
separately

Now that we can use WTF everywhere, we don't need to use skia::RefPtr.

I forgot to remove the virtual function in Platform.h and missed two clients of
this function. This CL switches those clients to keep their own network service.

R=eseidel@chromium.org, eseidel@google.com

Review URL: https://codereview.chromium.org/1230113006 .

This listens to both surface destruction as well as activity
pause/unpause.

R=abarth@chromium.org, abarth@google.com

Review URL: https://codereview.chromium.org/1230073002 .

Rather than hardcoding the size and presence of the notification area in Dart,
we now expose padding values on the view. These values are set to non-zero
values when there are UI elements that overlap the view. We currently respect
only the top padding, but this CL paves the way to respect padding in other
directions.

We still hardcode the size of the notification area in Java. A future CL will
retrieve this value from the Android framework.

Fixes #257

R=ianh@google.com

Review URL: https://codereview.chromium.org/1220353002.

This CL teaches Stocks.apk how to start from a skyx bundle name |app.skyx| in
the APK's asset collection.

Stocks.apk still actually starts from |snapshot_blob.bin| because we can't yet
produce skyx files as part of the build process.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1221033006.

The term ViewportObserver doesn't mean anything. This interface has evolved to
control the engine. This new name reflects that.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1222663003.

Please use ".dart" files instead.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1222483002.