Implement the basics for Safebrowsing for WebView

This CL implements the basics for Safebrowsing for Webview 

- A basic UI manager that decides (using a simple policy) whether or not show an interstitial
- A mechanism to call back to GMSCore for checking

[sgurun-gerrit only, 2017-01-07 18:14:41]

Description was changed from

==========
safebrowsing demo cl
==========

to

==========
safebrowsing demo cl
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation
==========

[Nate Fischer, 2017-01-13 23:23:37]

After the internal CL lands, you should apply a patch like this to integrate it:


diff --git a/android_webview/BUILD.gn b/android_webview/BUILD.gn
index 19a7de254777..8b189425e775 100644
--- a/android_webview/BUILD.gn
+++ b/android_webview/BUILD.gn
@@ -576,7 +576,6 @@ android_library("android_webview_java") {
     "java/src/org/chromium/android_webview/AwPrintDocumentAdapter.java",
     "java/src/org/chromium/android_webview/AwQuotaManagerBridge.java",
     "java/src/org/chromium/android_webview/AwResource.java",
-    "java/src/org/chromium/android_webview/AwSafeBrowsingApiHandler.java",
     "java/src/org/chromium/android_webview/AwScrollOffsetManager.java",
     "java/src/org/chromium/android_webview/AwServiceWorkerClient.java",
     "java/src/org/chromium/android_webview/AwServiceWorkerController.java",
diff --git
a/android_webview/java/src/org/chromium/android_webview/AwBrowserContext.java
b/android_webview/java/src/org/chromium/android_webview/AwBrowserContext.java
index d7d627193aa6..b1beb33ed84e 100644
---
a/android_webview/java/src/org/chromium/android_webview/AwBrowserContext.java
+++
b/android_webview/java/src/org/chromium/android_webview/AwBrowserContext.java
@@ -9,8 +9,8 @@ import android.content.SharedPreferences;
 
 import org.chromium.content.browser.AppWebMessagePortService;
 import org.chromium.content.browser.ContentViewStatics;
-
 import org.chromium.components.safe_browsing.SafeBrowsingApiBridge;
+import org.chromium.components.safe_browsing.SafeBrowsingApiHandler;
 
 /**
  * Java side of the Browser Context: contains all the java side objects needed
to host one
@@ -30,13 +30,23 @@ public class AwBrowserContext {
     private AwServiceWorkerController mServiceWorkerController;
     private Context mApplicationContext;
 
+    private static final String SAFE_BROWSING_API_HANDLER =
+            "com.android.webview.chromium.AwSafeBrowsingApiHandler";
+
     public AwBrowserContext(SharedPreferences sharedPreferences, Context
applicationContext) {
         mSharedPreferences = sharedPreferences;
         mMetricsServiceClient = new AwMetricsServiceClient(applicationContext);
         mApplicationContext = applicationContext;
 
-        // TODO(sgurun) is this a good place?
-       
SafeBrowsingApiBridge.setSafeBrowingHandlerType(AwSafeBrowsingApiHandler.class);
+        try {
+            Class<? extends SafeBrowsingApiHandler> cls =
+                    (Class<? extends SafeBrowsingApiHandler>) Class.forName(
+                            SAFE_BROWSING_API_HANDLER);
+            SafeBrowsingApiBridge.setSafeBrowingHandlerType(cls);
+
+        } catch (ClassNotFoundException e) {
+            // This is not an error; it just means this device doesn't have
specialized services.
+        }
     }
 
     public AwGeolocationPermissions getGeolocationPermissions() {

[sgurun-gerrit only, 2017-01-14 02:44:31]

Description was changed from

==========
safebrowsing demo cl
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation
==========

to

==========
This CL implements the basics for Safebrowsing for Webview 

- A basic UI manager that decides (using a simple policy) whether or not show an
interstitial
- A mechanism to call back to GMSCore for checking
==========

[sgurun-gerrit only, 2017-01-14 02:44:31]

sgurun@chromium.org changed reviewers:
+ michaelbai@chromium.org, ntfschr@google.com, timvolodine@chromium.org

[sgurun-gerrit only, 2017-01-14 02:46:40]

sgurun@chromium.org changed reviewers:
+ ntfschr@chromium.org
- michaelbai@chromium.org, ntfschr@google.com