Direct logging to Platform when available

All logging should be done via ERR() and WARN(),
which call angle::Platform's logError and logWarning,
if there is current Platform which supports logging.
Otherwise, ERR() is directed to std::cerr.

Misc fixes to keep tests passing.

BUG=angleproject:1660, angleproject:1644

Change-Id: I2bca33a021537185d0c236a3083789af3236b5f3
Reviewed-on: https://chromium-review.googlesource.com/434188
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/renderer/gl/FramebufferGL.cpp b/src/libANGLE/renderer/gl/FramebufferGL.cpp
index fcf5eb6..95e6e11 100644
--- a/src/libANGLE/renderer/gl/FramebufferGL.cpp
+++ b/src/libANGLE/renderer/gl/FramebufferGL.cpp
@@ -382,7 +382,7 @@
     GLenum status = mFunctions->checkFramebufferStatus(GL_FRAMEBUFFER);
     if (status != GL_FRAMEBUFFER_COMPLETE)
     {
-        ANGLEPlatformCurrent()->logWarning("GL framebuffer returned incomplete.");
+        WARN() << "GL framebuffer returned incomplete.";
     }
     return (status == GL_FRAMEBUFFER_COMPLETE);
 }