The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/aed77bf7b96062ead04616eeac810d25ae4d23a0

commit aed77bf7b96062ead04616eeac810d25ae4d23a0
Author: Gustav Sennton <gsennton@google.com>
Date: Tue May 01 14:14:44 2018

[android webview] Add support library support for WebMessage(port) APIs.

Provide chromium-side support for WebMessages in the WebView Support
Library.
We'll add feature flags for these APIs in a follow-up.

Bug:  813118 
Change-Id: I52a2576ae92f6051c4ce5ea7a68e1901598cfa02
Reviewed-on: https://chromium-review.googlesource.com/976125
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Commit-Queue: Gustav Sennton <gsennton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555034}
[modify] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/glue/java/src/com/android/webview/chromium/WebkitToSharedGlueConverter.java
[modify] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/BUILD.gn
[modify] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/boundary_interfaces/BUILD.gn
[add] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebMessageBoundaryInterface.java
[add] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebMessageCallbackBoundaryInterface.java
[add] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebMessagePortBoundaryInterface.java
[modify] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebViewProviderBoundaryInterface.java
[modify] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebkitToCompatConverterBoundaryInterface.java
[add] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/java/DEPS
[add] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebMessageCallbackAdapter.java
[add] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebMessagePortAdapter.java
[modify] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebViewChromium.java
[modify] https://crrev.com/aed77bf7b96062ead04616eeac810d25ae4d23a0/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebkitToCompatConverterAdapter.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec

commit a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec
Author: Gustav Sennton <gsennton@google.com>
Date: Tue May 15 09:28:09 2018

[android webview] (support lib) Add feature flags for WebMessage APIs.

To ensure support library methods calls are only called on webview /
support library versions where they're supported we use feature flags.
This CL adds feature flags for APIs related to WebMessages
(postmessages).

Bug:  813118 
Change-Id: Ic0d06df79da079a0d9c87ce09cd9fc720d6a244c
Reviewed-on: https://chromium-review.googlesource.com/1041931
Commit-Queue: Gustav Sennton <gsennton@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558646}
[modify] https://crrev.com/a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebMessageBoundaryInterface.java
[modify] https://crrev.com/a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebMessageCallbackBoundaryInterface.java
[modify] https://crrev.com/a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/util/Features.java
[modify] https://crrev.com/a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebMessageCallbackAdapter.java
[modify] https://crrev.com/a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebMessagePortAdapter.java
[modify] https://crrev.com/a6a894e433c55b20f7261db6cc2ea5bef6b2f5ec/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebViewChromiumFactory.java