[android_webview] Introduce AwAssets to reference assets inside the apk.

[android_webview] Introduce AwAssets to reference assets inside the apk.

This change introduces a utility class AwAssets, accessible by native,
which is able to retrieve references (fd + offset + size) of assets
inside the apk. This is to enable direct mmap of uncompressed assets.
This change does NOT introduce yet any change to the WebView apk itself.
At current state, no behavioral change is intended.

BUG=394502
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284238

[Torne, 2014-07-18 01:34:04]

lgtm

[mkosiba (inactive), 2014-07-18 05:49:05]

https://codereview.chromium.org/401743003/diff/20001/android_webview/java/src...
File android_webview/java/src/org/chromium/android_webview/AwAssets.java
(right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/java/src...
android_webview/java/src/org/chromium/android_webview/AwAssets.java:26: public
static long[] OpenAsset(Context context, String fileName) {
nit: openAsset (lower case 'o')

https://codereview.chromium.org/401743003/diff/20001/android_webview/java/src...
android_webview/java/src/org/chromium/android_webview/AwAssets.java:28:
AssetManager manager =
context.getApplicationContext().getResources().getAssets();
why not just context.getAssets() ?

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
File android_webview/native/android_webview_jni_registrar.cc (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
android_webview/native/android_webview_jni_registrar.cc:36: // Register JNI for
android_webview classes.
is the indent change really needed? the old version looked fine to me.
clang-format sometimes is too eager to reformat things

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
File android_webview/native/aw_assets.cc (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
android_webview/native/aw_assets.cc:25: jlong* arr =
env->GetLongArrayElements(jarr.obj(), NULL);
maybe add a JavaLongArrayToLongVector helper function to jni_array and use that
instead?

Also, check if the size of the array is wrong?

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
File android_webview/native/aw_assets.h (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
android_webview/native/aw_assets.h:18: // - fd: file descriptor to the apk. The
caller takes ownership of the fd.
argument names should be in || (so |fd|, for example)

[benm (inactive), 2014-07-18 14:59:18]

Thanks Primiano! Looking great overall.

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/w...
File android_webview/native/webview_native.gyp (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/w...
android_webview/native/webview_native.gyp:39: 'aw_assets.cc',
and the header

[Primiano Tucci (use gerrit), 2014-07-18 17:03:30]

https://codereview.chromium.org/401743003/diff/20001/android_webview/java/src...
File android_webview/java/src/org/chromium/android_webview/AwAssets.java
(right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/java/src...
android_webview/java/src/org/chromium/android_webview/AwAssets.java:26: public
static long[] OpenAsset(Context context, String fileName) {
On 2014/07/18 05:49:05, mkosiba wrote:
> nit: openAsset (lower case 'o')

Done.

https://codereview.chromium.org/401743003/diff/20001/android_webview/java/src...
android_webview/java/src/org/chromium/android_webview/AwAssets.java:28:
AssetManager manager =
context.getApplicationContext().getResources().getAssets();
On 2014/07/18 05:49:05, mkosiba wrote:
> why not just context.getAssets() ?

Done.

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
File android_webview/native/android_webview_jni_registrar.cc (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
android_webview/native/android_webview_jni_registrar.cc:36: // Register JNI for
android_webview classes.
On 2014/07/18 05:49:05, mkosiba wrote:
> is the indent change really needed? the old version looked fine to me.
> clang-format sometimes is too eager to reformat things

Ah, I usually tend to trust clang-format, but in this case, yes, it seems to be
wrong.
Filed crbug.com/395150

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
File android_webview/native/aw_assets.cc (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
android_webview/native/aw_assets.cc:25: jlong* arr =
env->GetLongArrayElements(jarr.obj(), NULL);
On 2014/07/18 05:49:05, mkosiba wrote:
> maybe add a JavaLongArrayToLongVector helper function to jni_array and use
that
> instead?
Done

> 
> Also, check if the size of the array is wrong?
Done

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
File android_webview/native/aw_assets.h (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/a...
android_webview/native/aw_assets.h:18: // - fd: file descriptor to the apk. The
caller takes ownership of the fd.
On 2014/07/18 05:49:05, mkosiba wrote:
> argument names should be in || (so |fd|, for example)

Done.

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/w...
File android_webview/native/webview_native.gyp (right):

https://codereview.chromium.org/401743003/diff/20001/android_webview/native/w...
android_webview/native/webview_native.gyp:39: 'aw_assets.cc',
On 2014/07/18 14:59:18, benm wrote:
> and the header

Done.

[Primiano Tucci (use gerrit), 2014-07-18 17:04:44]

+nyquist for the changes in base/android/jni_array.[h|cc]

[nyquist, 2014-07-18 17:25:37]

base/android lgtm

[mkosiba (inactive), 2014-07-18 18:29:44]

lgtm

[Primiano Tucci (use gerrit), 2014-07-18 20:07:02]

The CQ bit was checked by primiano@chromium.org

[commit-bot: I haz the power, 2014-07-18 20:09:55]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/primiano@chromium.org/401743003/60001

[commit-bot: I haz the power, 2014-07-18 22:50:48]

Change committed as 284238