ios fixes

skia_ios.mm
Get the app's Documents directory and pass use it to set the resource path.
This is a quick hack which will be replaced by a new application that is
a tiny shim around a command line tool.

SkImageEncoder.h
SkForceLinking.cpp
SkImageDecoder_CG.cpp
Add support for FORCE_LINKING so iOS sees the PNG encoder and others.

SkFloatBits.cpp
SkPoint.cpp
Handle denormalized numbers that are floored by the iOS ARM processor.

SkImageDecoder_iOS.mm
Remove empty encoder factory.

SkTouchGesture.cpp
Return early on empty state on touch rather than aborting (crashing)

JpegTest.cpp
Hal via stackoverflow.com says partial jpegs can be gray as well.

skia_test.cpp
Remove crash handler call for now to avoid link failure.

OverwriteLine.h
Remove fancy line overwrite for iOS.

Resources.cpp
Add interface to set resource directory based on runtime query.

BUG=skia:2736 skia:2737 skia:2738
R=reed@google.com, halcanary@google.com, mtklein@google.com, tfarina@chromium.org

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/373383003
diff --git a/tools/OverwriteLine.h b/tools/OverwriteLine.h
index b76c223..e8f0504 100644
--- a/tools/OverwriteLine.h
+++ b/tools/OverwriteLine.h
@@ -5,6 +5,8 @@
 static const char* kSkOverwriteLine =
 #ifdef SK_BUILD_FOR_WIN32
 "\r                                                                               \r"
+#elif defined(SK_BUILD_FOR_IOS)
+"\r"
 #else
 "\r\033[K"
 #endif