I am putting up a WIP CL full of Logs here (https://codereview.chromium.org/2735633004).

adb logcat output is here(https://gist.github.com/riju/4138c153ab54e9a6c3c9cff892bb0dd1) and a shorter one here(https://gist.github.com/riju/569b238223e20a02be32a1c72086f7fb).

My device is running "android version release = 6.0; sdkVersion: 23"

camera.putExtra("android.intent.extra.USE_FRONT_CAMERA", true);
or
camera.putExtra("android.intent.extras.LENS_FACING_FRONT", 1);
or
camera.putExtra("android.intent.extras.CAMERA_FACING", Camera.CameraInfo.CAMERA_FACING_FRONT);

did not have the desired effect, so tried to loop through all cameras and find the front facing one, and open the camera using -> manager.openCamera(mCameraId, mStateCallback, null)
I get that Front camera is cameraID=1, still Camera always opens facing that side it was facing, when it was closed last time.

Is there is a preferred way to open the camera facing front ?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/13d368e40bd49f076abb109ea3c875215098f744

commit 13d368e40bd49f076abb109ea3c875215098f744
Author: mcasas <mcasas@chromium.org>
Date: Tue Mar 07 22:12:26 2017

Add [Measure] to HTMLInputElement |capture|

To follow up usage before and after latest update
to the http://www.w3.org/TR/html-media-capture/ spec.

BUG= 698853 

Review-Url: https://codereview.chromium.org/2735893002
Cr-Commit-Position: refs/heads/master@{#455243}

[modify] https://crrev.com/13d368e40bd49f076abb109ea3c875215098f744/third_party/WebKit/Source/core/frame/UseCounter.h
[modify] https://crrev.com/13d368e40bd49f076abb109ea3c875215098f744/third_party/WebKit/Source/core/html/HTMLInputElement.idl
[modify] https://crrev.com/13d368e40bd49f076abb109ea3c875215098f744/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/97065e3acc9aed6ed78628114d19d327431f6b6e

commit 97065e3acc9aed6ed78628114d19d327431f6b6e
Author: Philip Jägenstedt <foolip@chromium.org>
Date: Fri Mar 10 05:55:45 2017

Link to the new input.capture spec and add a TODO to reconcile

BUG= 698853 
R=mcasas@chromium.org

Change-Id: I5d9b9e4f1dc7e985fe48a2392afb24eedae45b59
Reviewed-on: https://chromium-review.googlesource.com/452138
Reviewed-by: Miguel Casas-Sanchez <mcasas@chromium.org>
Commit-Queue: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#456005}
[modify] https://crrev.com/97065e3acc9aed6ed78628114d19d327431f6b6e/third_party/WebKit/Source/core/html/HTMLInputElement.idl

Hi Miguel and qinmin,

Last few days, I prototyped a native Android app for Basic Camera operations.
camera.open(front_id) works, but it needs a surface for preview.
I decided against going that route for this bug, as even if I get the preview working, all the controls user expect(from camera) in the interface will be hard to add.
So intent and then launch the camera app should be the way to do.
Uploaded a WIP patchset to the CL

summary ->
====
Intent camera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            camera.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION
                    | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
            camera.putExtra(MediaStore.EXTRA_OUTPUT, mCameraOutputUri);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1) {
                    camera.putExtra("android.intent.extras.LENS_FACING_FRONT", 1);
                } else {
                    camera.putExtra("android.intent.extras.CAMERA_FACING",
                            Camera.CameraInfo.CAMERA_FACING_FRONT);
                }

====
Output:
I see intent as => #Intent;action=android.media.action.IMAGE_CAPTURE;launchFlags=0x3;i.android.intent.extras.LENS_FACING_FRONT=1;end
=====

But still camera opens with "last opened facing mode".

Any suggestions ?

There is no standard, documented intent extra for the camera facing, when using ACTION_IMAGE_CAPTURE; only what's documented in the reference can be counted to be tested:

https://developer.android.com/reference/android/provider/MediaStore.html#ACTION_IMAGE_CAPTURE

Various Android OEMs may respect some kind of extra for this, but there's likely a variety of names for it; and if a user has set some other camera application (from the Play Store) as the default camera, that application may not respect that extra (or any other). 

So a facing field cannot be relied upon, unless you know exactly what camera app will be receiving the intent.

thanks @etalvala for the information.

Looks like iOS has some UIImagePickerController where you can specify to open the camera (UIImagePickerControllerSourceTypeCamera) and specify that you want front facing (UIImagePickerControllerCameraDeviceFront).

I was expecting something similar in Android.

@finnur is working on a File/Photo picker (https://bugs.chromium.org/p/chromium/issues/detail?id=656015)
and I wanted to use the "LAUNCH_CAMERA" part for this bug, but if the underlying Android API is not supported, let's see how far we can progress.

Yes, I am working on a File/Photo picker, and although the user will be able to launch the camera from it, the functionality around the camera intent should remain the same as it does in the current Chromium codebase. I don't think you have/should have much of a dependency on my work.

@finnur: Yes right, just wanted to keep in the loop.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8ccbf0490f18b6a6e3e4d004fbc27683cc215636

commit 8ccbf0490f18b6a6e3e4d004fbc27683cc215636
Author: foolip <foolip@chromium.org>
Date: Thu Apr 27 17:56:09 2017

Import HTML Media Capture web-platform-tests

R=rijubrata.bhaumik@intel.com,mcasas@chromium.org
BUG= 698853 

Review-Url: https://codereview.chromium.org/2848533002
Cr-Commit-Position: refs/heads/master@{#467735}

[modify] https://crrev.com/8ccbf0490f18b6a6e3e4d004fbc27683cc215636/third_party/WebKit/LayoutTests/W3CImportExpectations

The CL for implementing the HTML Media Capture spec change has landed. https://chromium.googlesource.com/chromium/src/+/08c2a170239dae6559f696d033fa1baf8bbef4ac

 Issue 772905  has been merged into this issue.